I'm not saying an edit, but making a sprite from scratch. With RTP as reference. Maybe even just the face image or promotional art or something.
And by little bits I mean, like... Okay say I'm making Harold.
So I make the base body, then the shirt, and pants, armor, tabard, hair, and so on.
But I save all the stuff separately, and reuse it to save time on another completely original character, who has like, the cloak and pants or Harolds bangs or whatever.
(Like the new Harold sprite would definitely only be able to be used with rpgm products... I'm pretty sure. It's reusing it to make other stuff I'm wondering about.)