Well timed. I've been going through this process as a non-artist forced to churn out some tiles for a game I'm building [1].

I started off simply cribbing all the tiles from Ultima IV for the Apple II, then gradually adding some rudimentary new tiles as the need arose. Starting with a pixel "rock" and "stick", changing the clothes on existing characters, then eventually gaining a bit of confidence and launching off on more complicated things. Eventually coming back and redoing all the "borrowed" tiles, and launching off into new, more detailed, characters and items.

"Constraints hide your flaws" got me a long way. I've relaxed those constraints a bit as I got better at shading, so it's easy to tell which tiles were drawn at what point in my "career"

[1] https://valtima4.com/, the Survival Crafting RPG you would have played on you Apple II in the '80s. It's essentially Valheim crammed into Ultima IV's interface.

Single player works up through the first couple bosses, but it's not really ready to ship into early access yet.