You should check out this twitter thread by Maddy Thorson, the creator of Celeste, on features that help a platformer game to feel better. Not all are relevant, but a few are essential like coyote time and jump buffering.
Another thing not listed there is related to jump buffering. If the player inputs jump before they've landed but could double jump, it should do a single jump (what the player probably intended) instead of consuming your double jump.