I do a lot of curiosity buying I buy it if I like the album cover I buy it if I like the name of the band anything that sparks my imagination. I still like to go to record stores I like to just wander around and I'll buy whatever catches my attention.
Sometimes a character is really based on research that you do. Other times it's just based on your imagination or perhaps your conversation with the director. Or sometimes all of the above. It depends on the movie and character.
