Appeal can be very much “in the eye of the beholder,” but that’s not say there aren’t some principles we can all agree on. Things to focus on are line quality, straights v.s. curves (line style/variety), proportion, and shape.
Freddie Moore, who supervised the dwarves in Snow White, is known for his appealing drawings. Frank Thomas and Ollie Johnston even said he was huge influence on the overall Disney style. The Freddie Moore Girl
Freddie didn’t really have a formula; it’s just how he drew. So, creating appeal can be hard to figure out, especially if it doesn’t come as naturally to us as it might to someone like Fred Moore.
But we can look at what we think are appealing characters and try to pull something from them.
Nico Marlet has some really appealing designs.
As well as Chris Sanders.
Some other things to look at:
I could put more, but really, what’s appealing in my eyes may not be as appealing to you or others here, so the best way is to go out and look for what appeals to you and to read up on the artists who drew them. Hopefully this helped! :)