Misty water colored memoriesssssssss. Sorry, this photo does it to me every time-- :P
A friend of mine uses photos of models and actors to represent characters in her novels. She's very precise in whom she chooses to carry the load in the story. She works off their expressions and posture, I'm in awe every time she pulls out the portfolio and "introduced" to her cast.
I have no such luck. I have a vague idea of a naked Daniel Craig for each of my heroes and I'm good to go.
Do you have a clear idea of your characters beyond the basics? I can barely finish writing a character bio without thinking I'm suffocating my muse - talk about overthinking. ;)