Yo Twirly
To begin with, try to make just a bit bigger sprites. It's hard to learn how to make it look detailed and not messy with such a small piece of art. I had a hard time figuring out
how to make it look good with so little space, but I started to make larger chars. and I made them smaller every time. I think a big misstake people do when doing small sprites
is that they use too much colours. It needs to be simple but still detailed.
I have a few old pictures of mine that could maby help you:
These are a bit larger sprites, not very hard to shade. You can use a bit more variety in colours on this one, it won't get messy that easy. However, Its important not to pillowshade anyway! (The picture is a bit political, I hope it won't be any troubble. Its one of the parties in my country wanting to get in to the European parliment)
Here is a small sprite from a pirate platformer I made a long time ago, here it's very important to have a big difference between your bright colours and your dark colours, to make a better contrast on a smaller space. If you start using a lot of colours, many highlights. It will end up looking very messy and actually less detailed from what you really want it to be.
This is of course a matter of style and taste, but it is a good way to learn.
Hope it can be of any help!
Good luck!
