Hi! Welcome first off.
AAO has some useful spriting tutorials in their "Art Guides" section. You can view these here: https://aaonline.fr/forum/viewforum.php?f=51

I've also made one in my sprite thread but honestly it needs updating.

I'm trying to determine whether to attempt to make them fully from scratch, or take the easy route and recolor/edit canon sprites to represent my own characters. What do you guys think?

I'm still new, but I think it depends on what you want the feel of the character to be, and how much its going to look like the original character.

I think both ways are really fun, its just that recolor and/or editing existing sprites takes a little less time, plus, any ideas you might have for the character might be harder to imagine because something already exists in it's place. But the proportions are going to be spot on no matter what.

Best thing to do is to not lose sight of what you're drawing to begin with.