Yey! These are too cute!
Suggestions for the first one:
Maybe you could switch the eyes around, unless he's squinting a bit. Only because the eye the farthest from the viewer should be smaller in relation to the one closest; it's the whole issue of perspective so it's tough to figure out.
Its really great though, I like the colouring!!
The scond one is really cute!
Suggestions for the second one:
Maybe use less line for the creases in his pants; line is a tricky element, and it's always best to go with 'implying' the folds in clothes rather than boldly stating them. The cuff on the bottoms of the pants and the knees are perfect; but around the groin region it could stand to use less and shorter strokes.
Feet are /really/ hard to do, you did an excellent job!!
General tip for line art/sketch problems:
I find it really helps if you look at your sketch in a mirror. If it doesn't look right somehow but you can't quite figure out which part is the problem, cart it over to a mirror and it'll show you the problem right away!
Anyway, I hope I didn't offend you, I'm just throwing out ideas that might help you (or anyone else reading this) in the future!