Still Game returns: behind the scenes on the hit BBC comedy

A grey and cloudy August morning finds the cast and crew filming in the city's Ruchill Park. Within minutes, the leafy space is abuzz with activity as monitors are wheeled into place, cameras set up and props organised.

Overseeing proceedings is director Michael Hines whose demeanour is akin to an orchestra conductor as he points this way and that, indicating where he wants everyone and everything to go.

Hines has been at the helm for almost all 50 episodes of Still Game that have aired to date (or as he clarifies: "I have done 49-and-a-half – I didn't do the pilot episode, but I did reshoot half of it …").

He is gregarious company with a rapid-fire, machine gun delivery that serves up a raft of anecdotes. Hines first worked with Kiernan and Hemphill – who play main protagonists Jack Jarvis and Victor McDade in the show – on the Hogmanay special of Chewin' The Fat in 2000.

"We have got to a situation now where the three of us completely trust each other," he says. "They trust me to take their scripts and go make it."

Death is a theme that looms large in the latest series of Still Game. Bruce Morton has joined the cast as the ominous sounding "undertaker" and ever since word leaked out that a long-standing character will depart Craiglang in a coffin, there has been feverish speculation abound.

Hines is keeping tight-lipped about who is set to exit the show with the cast and crew sworn to secrecy. Viewers are being told to brace themselves for a darker undercurrent to upcoming episodes, with the bookies taking bets on which fan favourite might meet their maker.

Funeral director Iain Duncan Sheathing – played by stand-up comic Morton (who famously introduced the show's co-creators Kiernan and Hemphill in the 1990s) – has been dubbed "the living embodiment of the Grim Reaper".

There will be a touch of Hollywood glamour arriving in Craiglang, too, with US-based talk show host Craig Ferguson playing an old friend of Isa's who returns to Scotland after living in Los Angeles.

New faces – and the departure of existing ones – are all part of the natural evolution of Still Game. "It has been through so many changes, like Doctor Who," says Hines. "We did the first set, it got massive, we had a break, did the show [at the SSE Hydro] and then came back."

Filming in the park alongside Kiernan and Hemphill is Gavin Mitchell, who plays Boabby, the long-suffering barman from Craiglang's local pub, The Clansman.

It takes a moment for the penny to drop. Wait! Boabby isn't pulling pints behind a foot of polished wood. He doesn't have his trademark tea towel over his shoulder. And that food in his hand certainly doesn't look like it has crawled out of The Clansman microwave. What on earth is going on?

Well, that would be a spoiler. Let's just say we'll see a very different side to Boabby this time around. It may even stir feelings of empathy about the grumpy and sarcastic sod that will surprise you …

Mitchell is on sparkling form as he pops over for a chat during a break in filming, the actor clearly relishing being back in character.

The previous take was halted when the trio descended into unscripted laughter – corpsing as they call it in the business – and Mitchell is still fighting bubbling giggles as he walks off set.

Kiernan is apparently getting the blame for that one. "He's brilliant and can just move his eyes or do a quick head turn and make me laugh," grins Mitchell. "We know how to tweak each other's chuckle muscles.

"Once you've gone, it is hard to get it back. Sometimes Michael slaps our wrists and tells us to go for a walk to calm down. I didn't need that today. I was almost professional."

Up close his hair – or rather Boabby's mane – is a sight to behold. Mitchell gives the long, dark wig a dramatic flick. "It's like Aslan," he says, referencing the lion in CS Lewis's The Chronicles Of Narnia.

"If only it was my own. It is phenomenal. Boabby's hair has grown in colour, length and volume. I'm like one of Charlie's Angels now."

When does he cease being Gavin and morph into Boabby: it is the wig, chunky gold jewellery or retina-searing shirt collection? "It is kind of odd," he muses. "The final touch is actually when I'm in The Clansman and put on the dish towel. If he doesn't have his dish towel, I feel a wee bit naked.

"Boabby always has his towel. That and walking into The Clansman which, for Boabby, is almost like his Tardis. Last series the first scene was in Navid's which felt very strange. It was fish out of water. I was like: 'Hold on, I don't belong in here and I don't have a dish towel. I don't know how to act ...'"

Death is in the air. When did the cast get a whisper of that? "We were as surprised as everyone else because we don't find out until we get the scripts," he says. "Then we were like: 'Oh, my God!' The stakes are high throughout this series. Mortality plays a big part.

"It has always been a mark of Still Game and the brilliant writing that, in among all the laughs, there are really serious issues and we address that. It can turn on a pin from laughter to tears."

We're interrupted as Mitchell is called back onto set. He gives a theatrical wave, adopting a comical, hammy accent: "Excuse me, I must dream weave …"

He stalks off leaving everyone doubled up with laughter. I'm curious to learn more about the food being used in the scene which includes something called a "beefy bake" – a savoury, meat-filled pastry not a million miles from the trademark staple of a well-known bakery.

According to the art department, they typically bring six duplicates of each prop. With beefy bakes that figure is doubled for very good reason. "Normally the boys like to eat them," explains one crew member. "But today they don't seem to be in the mood ..."

A few minutes later, Mitchell returns and takes up the thread again. "There are loads of surprises this series and quite a lot of good stunts," he says.

What kind of stunts? "Well, you saw an amazing stunt there with a beefy bake," he deadpans. "What more can I say? Not everyone can handle a beefy bake like that. That took weeks of training. We all had to go to a beefy bake course …"

There's a few more takes as a bin lorry trundling past, the drone of a low plane overhead and the rhythmic whirr of a street sweeper all momentarily disrupt filming.

At one stage an over-excited, poodle-type dog comes running up, its piercing bark splitting eardrums. "Shut up, you yappy b******," comes the cry as it makes a beeline for the actors.

They cheerily take it all in their stride. "Everyone says it is really glamorous," says Hines. "But at 6am, when you are freezing your b**** off, it is less glamorous with some ned going home from the night before shouting: 'Two pints, p****'.

"Then we look at each other and go: 'Ah, the glamour …' It is mentally tiring, but I love it to bits."

With the scene finally wrapped, it's like Challenge Anneka as equipment and props are loaded up and taken to the next location.

We arrive in Garscube where a special sporting event unfolds (again, no spoilers, but if you look closely you may see a certain writer from The Herald Magazine doing her best Edvard Munch's The Scream impersonation in the background).

Someone kicks a stray ball towards the goals where Hines is standing going through his notes. He makes a stellar save. "You don't get Spielberg doing that," he says, without missing a beat.

Over lunch I grab a chat with the show's co-creators about what the new series holds. Kiernan has just woken up from a nap and Hemphill is sporting a headband. "It is a John McEnroe tribute," he jokes. "Keeps the wig in place."

Both cite working with Morton and Ferguson among their highlights of the latest series. What are the other standouts?

Kiernan: "One of the cast will die in this run. It has been exciting trying to keep that contained because after it was put in the newspapers, Ladbrokes had odds on it. Whenever we are on location everyone keeps asking us who it is."

Hemphill: "The supporting artists have been asking us as well." Kiernan: "Because they want to get a bet on it, but we've not told them."

How do they feel about killing off a long-standing character?

Kiernan: "We have written so many hours of it that something has got to give. The cast can get a wee bit bigger, but it can't stretch much further than it is just now. "When your time is up, it's up. It is like Crossroads or Coronation Street – they never know when a taxi is coming round the corner."

Hemphill: "If you are talking about old age these factors have to be addressed in the show because death is part of life."

How did the cast member take it?

Hemphill: "They just arrived one day and their Winnebago was empty."

Kiernan: "There was somebody else in there: 'Can I help you, mate?'"

Hemphill: "'Did you not get the memo?'"

They break off laughing, before Hemphill quickly clarifies: "No, these things are discussed over a long time. We don't like to shock anybody."

They are clearly giving nothing away. "I know, we cannae be drawn, it's terrible," says Kiernan.

Back at unit base is where the magic begins each day. Costume designer Donna Bryce-MacLeod explains the wardrobe logistics for Still Game that require thousands of garments every series.

"I read the scripts and then do a breakdown for each character for each episode," she says. "Normally, they will wear something different each day. But it depends what happens. If somebody has been sick or throws their drink [in a scene], you need double costumes.

"Everything gets fitted on the cast before we start filming. It is then altered. A lot of the work is done in prep and every costume is plotted. You might have three changes a day."

They don't want the outfits to look brand new either. "We break it down by sanding it or using dirt, sometimes burning it if it is made from wool," she adds.

I spot some sombre looking outfits hanging up nearby. Suitable for a funeral, perhaps? I crane my neck trying to get a sneaky peek at the name tags. Bryce-MacLeod jumps in front of the rack and smiles. "Do you not like my colour palette?" she jokes.

There are other considerations too. "If you have got an actor who is slightly slimmer, you will give them some padding," says Bryce-MacLeod. "You sometimes have to fatten them up."

She disappears into the back of the trailer and calls across to a colleague. "Do you know where the tummies are?"

From a shelf, Bryce-MacLeod pulls a cushion-like tummy that Sanjeev Kohli wears as shopkeeper Navid Harrid. It is soft and squishy and even has a belly button sewn in which – ignoring the aghast look of the BBC Scotland publicist – I can't help but poke my finger into.

I'm swiftly whisked away to the next location on our whistle stop tour: the hair and make-up department. It's a fascinating place, albeit a tad unsettling to be gazing at multiple disembodied dummy heads adorned with spare moustaches, beards and wigs.

"That one belongs to Jack/Ford," says hair and make-up designer Julie Dorrat-Keenan, explaining that the moustaches are made from very fine lace with each hair individually knotted. I give it a little stroke (when you've already put your finger in a fake belly button, boundaries cease to exist).

The biggest part of Dorrat-Keenan's job is "ageing" the cast to make them look like pensioners. She uses clever techniques such as applying layers of latex to create wrinkles. It can be a time-consuming process.

"It takes about an hour for each person," she confirms. Attention to detail is crucial. "We colour up the hands and bring out the veins," she says. "We put liver spots on and add a couple of layers of latex over the backs of the hands. You try and cover all bases in case there is a close-up."

How difficult a material is latex to work with? "It can be tricky," she admits. "With some latex you need to stretch the skin to create the wrinkle and then dry it with the hairdryer.

"With the type of latex we use, it just wrinkles the skin without having to stretch it. That frees up time and means we can put the wig on while waiting for it to dry. Latex is quite robust, which is good, because it helps to seal any of the shading and character detail underneath.

"The downside is you can't colour on top of the latex because it grabs any kind of colour and it is quite shiny. Powder won't de-shine it."

But it is not without potential pitfalls. "With latex you have to be careful if it gets wet. If you are out in inclement weather for hours on end, it can turn white. It's the same if someone is particularly sweaty. Once it turns white there is no going back. You need to take it off and apply a fresh layer."

Casting my mind back to the matter of beefy bakes, does Dorrat-Keenan need to patrol for crumbs in the faux facial hair? "They take their moustaches off for lunch. They are supposed to come into make-up and have it removed, but Ford just pulls his off. He is the rebel."

Fans of the show will notice that while Hemphill has blue eyes in real life, his on-screen alter ego Victor McDade's are hazel brown. Again, there is good reason for this.

"He has such piercing blue eyes and very dark rims to his eyelashes – detail that can make you look more youthful – so we had to find a way of taking that brightness out of the eyes," explains Dorrat-Keenan.

"I would have liked originally to have gone for a foggy look to the lenses, but back in the day when we were doing the pilot there just wasn't the time or the money, so we went with a hazel coloured lens to take the bright blue out."

It is meticulous and painstaking work, but there is banter aplenty. "Oh God, yeah," she says. "There are days when that make-up trailer is rocking with everybody laughing."

Still Game returns to BBC1, Thursday, 9.30pm