I found a still from Brian DePalma's "Carrie" and got this idea for one of those retro posters that look like they've been crushed between porn magazines for 30 years. I changed Carrie's expression a little because I wanted to bring out the sympathy you feel for the character.
Carrie was sketched in with pencil, attacked with watercolours, and sketched over again with pencil and pens. After scanning it in, I used some vintage textures and filters on Photoshop over the original poster's credits at the bottom. The font used for the title is the same one used in "Apocalypse Now".