Here are some tips, I am no flash artist... hell I can't draw for shit really, but read it anywho, as it helped mah artistic friends
Before you start drawing, just think about what your character is gonna be like: Mean, Horrible, Slik, Shy.
Just try and get as many as possible that would relate to the character in your head.
Then think of what hair would go with them, then eyes... thinking about size and proportions and how they will enact with each other.
And work your way down with nose, body proportions/height and anything else.