Feedback on some pixel art

[Divitos]

I'm very new to pixel art (by very new I mean I've experimented with it off and on but have always been terrible, and just decided today that I wanted to get serious about it and try to learn it). I'd love some feedback on an RPG character I did based on a piece of pixel art made by Heartbeast in a Let's Pixel video, as well as a ukulele that I made based on a ukulele sitting across from me.

I know these are absolutely terrible so don't be afraid to give it to me as it is, I'd just like to know what kind of things I can keep in mind next time and do to get better.

Character:


Ukulele:

[Pusty]

I don't think the Ukulele looks too bad lol
But Character can be improved in many ways
The foot look look weird, the shoulders as well.
For the Character you should look into anatomy lol
I hope this helps