Here are some tips :3
It is better if you color the editable (any color, even purple!) so that the people who color can use lock alpha. (be sure to put color on a different layer than the lines!)
Make the whiskers thinner. they are hair, right? they are not really that thick.
A cat's face is not a perfect circle, but I can't really explain what shape it is really supposed to be...XD
Use a reference!! look at real cats.
try using a more realistic kind of eye, it makes a huge difference :3
I am not trying to be mean, just giving you tips :3
(my worse fear is that I will give someone tips and they will take it as an insult and get mad at me

)