6. ...And Making Sure They're Supported

Though Andrea Arnold ended up casting the established likes of Michael Fassbender, he first plan was to find an entirely untested cast. 

“I originally wanted real people for everyone in Fish Tank and I had my eye on a man who works in my local park, a man who empties the bins. He was a perfect Connor. I wonder what he made of me watching him so intently every time I saw him.

"But then I began to think it would be interesting to have someone with experience, mixed in with Katie’s innocence as that would echo the relationship in the film and could work well.”

Fassbender had notched up serious acclaim for Hunger, but that wasn't what sparked Arnold's choice.

“I saw Michael for the first time in a clip from Wedding Belles, an Irvine Welsh film. I hadn’t seen Hunger or even known about it at that point, though I became aware of it later.

"I though he was very charismatic in Wedding Belles and that was an important quality for Connor. I made a decision without meeting him on the strength of that clip really because he felt right and I trust my instincts in that way.

"I don’t like to question myself when it feels right so just went for it.”

It was a similar story when Arnold went looking for someone to play Mia's mother. "I originally was looking for someone real for Joanne too, someone who had lived like Joanne. Someone harder.

"Kierston Wareing does not have that, but she had honesty about her, and openness and I guess a kind of innocence that was very attractive.

"It was different to what I had been looking for but still felt right. I love that about film making, you set out with a particular idea but it changes, evolves, and redefines itself daily.

"You have to embrace that. If you have the story in your heart, and hold onto it, the thing you care about can still be there even when everything changes, even when you lose the most important things, even when you despair you can often still find a way.”

After rounding up the rest of her cast, she could kick off production…

Next: Shooting Fish