When you draw a hat, make sure you draw the head underneath the hat first, and then draw the hat slightly bigger than yhe heat. Same goes for hair except hair comes further off the head.
Your lines are also really messy, make sure you zoom in and clean up your line art. It’s more noticeable on tuxedo guy.
Also when you watermark, if you don’t use your username the watermark is not very helpful. Part of the point of a watermark is having your user on it so if someone reposts it, people can trace it back to you or you can prove you own it. I’ve had improperly watermarked art stolen before, it’s more appealing to claim I suppose.
A minor edit. On the first picture, the hat has a round-ish brim. Meaning, the shadow on the face shouldn’t be too horizontal, but instead shaped like a U.
Just an opinion but I think it’d look better if you had did the line art on the shirt as well.
And, as previously mentioned, your line art isn’t too good. Its a bit wobbly in certain places.
7.1 Do not create topics asking how much you should sell assets for; these will be considered spam.
7.2 Do not create topics asking users to rate your assets. Asking for feedback is fine, but asking for a rating (e.g. X out of 10) will be considered spam.
I think you still need more practice. You need to develop a light source and stick to it. Also, you may want to go back and clean up your lines a little.