Ideas for my thriller opening

In the half term Lauren and I planned out generally how our film opening is going to look like, with camera shots, the scenery that we will be using, the cast of actors we will need and the basics of how the opening is going to look like.
We have decided what our story line is going to be from the inspiration of the  film we watched, The Black Swan.

• The  main character is: A teenage girl who suffers from a psychological disorder which occurs when she is stress or feeling nervous.
• She sees things that aren't really there.

The general idea of the film opening:

• The scene starts we a girl and her friends walking back from school one day happily chatting. Once she leaves them to go her own way home she begins to see children swinging on the swings and playing on the see-saw in the park, which aren't there. The lighting will be in black and white with Foley sound of children creepily laughing.
• She then lets herself into her home and goes to take a shower. We know that when the steam covers the mirror in a bathroom, fear of the unknown can make people on edge, so we wanted to create this in our film opening.
• When she gets out of the shower she looks into the misty mirror and suddenly sees a dark sinister figure of a man staring back at her.
• She freaks out and runs to her room to ring her mum. She calls her mum and whispers in a petrified voice " Mum I think its happening again". As she puts down the phone she turns her head to see a man dresses in black sitting close to her bed staring at her.
• The camera cuts to a close up of her face to show the fear as she lets out a scream and the shot ends with a black screen.

We haven't planned it all and we need to chose our actors and setting carefully but we think we have some ideas.