KAHLEEN Crawford grins as she reveals a very odd schoolgirl pastime. “From quite a young age I’d watch a lot of black and white films with a family friend who looked after me after school every day. Afterwards I’d write the name of the actors on a Post-it note and keep them in my bedside drawer.”

She adds, laughing: “I know, it’s totally weird. But I suppose it was an indicator.”

Not half. Crawford still collects information on actors, indeed she builds up files, watches them assiduously, and has in fact made a career of it. Crawford is one of the UK’s most successful casting directors, the gatekeeper to the acting kingdom in which she has found the talent to appear in a range of successful films, TV dramas and soaps.

However, the success of her operation – she is based in London, with a Glasgow office – didn’t come easily. Coveted work such as Ken Loach movies and high profile dramas had to be earned and Crawford’s journey itself is the stuff of inspirational TV drama.

Picture this, after pushing aside parental suggestions of a career in forensics (her dad is a scientist), Crawford opted to study film and television at the University of Glasgow, with the idea of becoming a film editor. After graduating, her first attempt to climb the ladder saw her move to London for a job with a TV production company as a runner. But the inveterate keenness and enthusiasm she brought with her counted for little: runners were expected to work for around a pound an hour and do weekends for nothing. “This was the culture 17 years ago,” she sighs.

What was also the “culture” was bosses acting like screen divas. When one threw a hissy fit on discovering the decaf Earl Grey had run out, Crawford realised she was in the wrong movie and ran for the door.

“I was so miserable I kicked the door off its hinges, packed up my Fiat Punto and drove back home to live with parents. I figured I’d take a couple of weeks and then head to Italy for the winter season, to work in a bar, perhaps take a year out.”

Her parents, however, had other ideas – their daughter should think about her future, “sort herself out.” But what to do? The film editor idea had evaporated. “And I had no real idea of what producers and directors do.”

The idea of becoming a casting agent hadn’t yet formed. After all, it’s not the sort of career where your 12-year-old self wakes up and thinks, 'Where can I find a blue-eyed actor who can inhabit the character of a psychopath, and offer a decent hillbilly accent?'

“All I knew was I was obsessed with cinema and actors and body language. I loved to study mannerisms, even my parents’ friends after a couple of glasses of wine.”

Crawford, born in Glasgow in 1979, reckoned she wanted to work with actors and decided to call Scottish Screen, figuring they would help find her a job. It was a completely naive approach to a career move. And it worked.

“It was suggested I call Maryam Hunwick, an actor’s agent, who was great and she offered me a cup of tea and a chance to talk about a career. I was then put in touch with Gillian Berry, a casting director who worked on My Name Is Joe with Ken Loach.”

Serendipitously, Berry was looking for someone to join her agency, given the recent growth of filming in Scotland. “There was no ‘let’s see your CV,’ or ‘What are your career plans?’ She was desperate for help and said ‘When can you start’?”

Crawford adds: “It was all total fluke, and suddenly my plan for the ski season was gone.”

The Post-it years had been worthwhile. Crawford immediately loved her job, being hired to find the talent, match it to the role and hope the director or producer agreed with her recommendation; a little like the Early Learning Centre shape sorter puzzles for children, but with human shapes.

She thrived in working with the likes of director David Mackenzie on The Last Great Wilderness and Kenny Glannan’s Gas Attack. She’s found talent for Peter Manuel drama In Plain Sight, a new Netflix series and the upcoming drama, The Miniaturist.

“Each production has a character of its own, being in casting is about adapting to the different processes,” she explains. “You sometimes deal closely with the director, sometimes the producer, at times you look to the financiers to work out who to suggest.”

It’s a psychological exercise, tuning in to needs. Crawford says: “At times it’s a battle between one person and another. That’s when you become a negotiator.”

Crawford has to know the acting landscape better than she once knew the routes to the clubs and bars of Glasgow’s west end. “A lot of is finding young people on the rise, or when an actor has personal problems but you know a better performance is in them. You need to watch European television, the Irish, the Canadian, and stay on top of London theatre.”

Don’t actors' agents try to railroad her into meeting/hiring their clients? “Sometimes, but that’s not a problem. All you have to do is see a person, not necessarily hire them, and sometimes you can have a look at someone on tape.

“At times however an agent may say their client has to be offered the part, they won’t audition, yet you know if a part requires chemistry with another actor. That can be tricky.”

Does she get bribed with weekends in St Moritz? “No,” she laughs. “Sometimes you get a box of candles. Independent cinema doesn’t work like that.”

At times, relations can be fraught. Actors’ careers at stake, mortgages, reputations. “We’ve had punches being thrown, lots of people crying, men and women, children. We’ve had agents come back (apologetically) and say ‘Can we talk about what happened in the room today?’

“We’ve had occasions when it’s all gone awry. Sometimes people bring ‘behaviours’ into a tight company space. They become bombs that explode.”

By “behaviours” does she mean drug abuse, actress chasing . . . “All of that. But we have to allow people to evolve, all of us. We become a different person. And sometimes great talent arrives with trouble. Sometimes you have to take a punt.”

Crawford struck out on her own 10 years ago after a partnership with casting director and actor Des Hamilton came to an end. It was tough at first. “In the first year I was paralysed with fear. I was on my knees financially, I made no money, couldn’t pay my bills. I had bits and bobs of work, the odd commercial but it wasn’t enough.”

For a woman who had always paid her way this was anathema to her way of being. “I reckoned I’d have to go back to working in a bar,” she admits. But perseverance, a growing reputation and a little luck changed everything. One day, the door knocked in the form of River City, asking her to find talent. Rebus followed and Crawford was on a roll.

Crawford’s animated voice reveals she loves her work, particularly when it comes to casting young talent, discovering the likes of Iain De Caestecker, who would go on to star alongside Ryan Gosling in Lost River.

She has brought older actors, class acts such as Sandy Morton into River City as hard man Billy Kennedy, played from leftfield by casting English actors such as Kate Rutter as Dr Miriam Stubbs.

What about the Harvey Weinstein sex scandal? Has she met British Harveys along the way? “Not to the level of Weinstein but I’ve been lucky because my parents nurtured good instincts. When I was 11 I told my mum someone was making me feel very uncomfortable. Her advice was not to scream and shout at the person but to step away and not go to gatherings where that person was. It taught me I didn’t have to accept that.”

She adds: “Maybe that’s why I’ve avoided the party in Cannes or not to back to a hotel room.”

Actors are often stereotyped as needy show-offs. Is that sometimes accurate? “That’s true,” she says laughing. “They’re not firefighters, or teachers or doctors but they’re brave. And they go out and do what they do and the value of entertainment is huge.” She adds: “They’re a special breed.”

She should know. She married one, in Outlander star Steven Cree. They met many times over the years during castings. Then four years ago Cree asked her out. “Timing,” she says, smiling.

Yet, while Crawford clearly adores life as a shape fitter, her career has created an odd irony. The one-time film buff can no longer sit down and relax over a film or a TV drama. She knows the actors, their faults, their quirks. The illusion is lost.

“I can’t remotely enjoy anything,” she says with a mock sigh. “It’s not relaxing anymore, although that’s probably why I watch more foreign language. At rare times I can get carried away with a theatre show, such as seeing Yerma with Billie Piper at the Young Vic; part of me went on a journey. But I can’t enjoy television unless it’s foreign and I don’t know anyone.”

No matter. Demand for her talent suggests she won’t be returning to bar work anytime soon.

“I hope not,” she says, smiling. “But if it came to it, I would.”