Deyn - who retired from modelling earlier this month - appears in Luis Prieto's remake of Pusher as the put-upon girlfriend of drug dealer Frank (Richard Coyle).
In an interview with Movieline, Deyn detailed how she used her modelling past to help prepare for the next phase of her career.
"[I] studied [acting] at college, and I didn't really know what I wanted to do and I kind of fell into modelling," she revealed. "I had a 12-year job on my plate, which was amazing, but what I did realise while modelling was that I did want to do a job that was creative."
The actress continued: "I really enjoyed creating a character when I was modelling, and I was like, 'Wow - I can take that to the next level and create a character in a movie'. So that was the evolution of what I wanted to do."
Deyn went on to suggest that she still considers herself an acting novice, despite her roles in Pusher and Clash of the Titans.
"I'm a young actress, starting a career - I read scripts, I audition, and I get it or I don't get it," she explained. "I don't expect that because I was successful in one field that I will then get a ride of passage into another.
"I know that I've got to work hard and deliver the goods, and I've got to do it, and show up. I liked Pusher and I especially liked how English and gritty it is, because I like to watch that. So I auditioned for it, and it was in their hands whether I did it or not."
Pusher is now playing in the US and the UK.
> Agyness Deyn, Peter Mullan join Terence Davies's Sunset Song
Watch a trailer for the film below: