i found a tutorial once that gave me some good ideas, i forget where it was though. But i have used it ever since. I put a thin white curtain over a table and had a female friend of mine lay her head on the edge of the table with her hair going down the curtain. I then put a bright light behind the curtain and took a picture of her hair from the other side. This gave me an incredibly realistic looking transmap that i have been able to edit and apply to nearly every hair prop i have used since.