hello!! that's a hard question actually! 😭
i've definitely seen a lot of tutorials + done studies (i really enjoy doing studies actually!) and have just drawn lots of the same stuff over and over, which must have slowly built up art skills, but i can't think of a specific tutorial or study that really changed how i draw or unlocked some crazy skill
still, here's some that i thought were inspiring or useful! i am trying to learn how to draw like professionally though, so this stuff might not fit what you wanna draw!
character design (a lot of qrbits stuff is very good), sketching, storyboarding, environments!!
i also don't know or have a lot of inspos by name besides my friends and amazing people here on toyhouse, but i get inspired by random art on pinterest, cool things seen in daily life, and media like youtube videos, shows, games, etc.!
if you wanna know about anything more specific i might be able to give a clearer answer!