Bubble play motivates kids to clean up
Okay, maybe this is just barely a hack, but I have a 2.5 yo and a 4 yo, and getting them to pick up their toys is always a struggle. However, I have discovered a good way to get them to help -- they really love playing with bubbles (i.e. I or they blow basic soap bubbles and they dance and catch them), so the new rule is, to play bubbles, they have to pick up all their toys and books off the floor of the room we will be playing in -- so they don't trip and get hurt (which they are old enough to understand). And parents pick up all the parent stuff that ends up on the floor. (oops) Cheerful cleanup with built-in reward!
The bubbles are great, but in my opinion, the hack here is the mindset change required to think this up. The focus is taken off the mundane, chore-like, "fun's over" job of cleanup, and instead placed on the much more attractive "let's play bubbles."
One may argue that kids need to simply learn to obey their parents, and "wrapping" a necessary chore inside a game obscures that. But I find that at such a young age, those lessons are lost on all but a very few kids with unusually compliant temperaments. With my family at least, these sorts of lessons are better learned through experience ("Hm. It's more fun to play when the space is cleaned up.") than lecturing.