I’ve enjoyed Krita and I think it’s the best I’ve found so far, there are just a lot of keybinds to change to make it more streamlined. I never had much luck with GIMP either

I've been trying it for about half an hour and yeah this is great so far! I managed to create a custom brush and it does what I pretty much want to the best of my ability. The UI for brush settings looks like you can do a lot with it.