More often than not, my main characters will start off with black hair, and end with red. They'll have a tattoo in the beginning that never ever comes up again. And from beginning to end, their eyes will hit the entire range of the color spectrum. If you were to read the character description in the beginning, and try again at the end, it would seem like two entirely different people with the same personality.
My solution? A character profile.
I make a new one for each story idea, since each story will need certain traits listed. For instance, if I'm writing a YA Science Fiction story about various aliens living on one planet it might look something like this:
Age:
Height:
Race Name:
Skin Color:
Skin Type:
Special Markings:
Number of Hands:
Number of Eyes:
Hair Type:
Hair Color:
Special Features:
Etc.
Height:
Race Name:
Skin Color:
Skin Type:
Special Markings:
Number of Hands:
Number of Eyes:
Hair Type:
Hair Color:
Special Features:
Etc.
And if I were writing about normal humans with normal features it would be more limited to basics: hair color, eye color, height, weight, skin tone, special markings, age, full name, birthplace, birth date. Most of the time my characters have seven pages worth of profiles, with everything from the basics to a characters fears, and likes and dislikes. Before I'm done I even have my main characters favorite movie documented.
Before I'm done my characters are as real to me as actual people and it helps me keep my stories straight.
How do you keep your characters straight? Are you a fan of the character profile or are you more of a "write now, fix the hair later" sort of writer?
What is the most important question you have for your main characters?