Rewarding kids with things they get to do instead of things they get to have. When they do something good, they pick from the jar and get to do things like stay up a little later or play outside a little longer . . . etc. (Note: the site this is pinned from isn't very good, so just use this picture as inspiration).
Playroom gallery wall with rotating artwork display. Post includes tutorials for making clothespin frames, crayon art, & chalkboard + some absolutely genius tips for how to arrange & hang a gallery wall!