Occasionally we use a little reverse psychology on our kids to get them to clean up. We would say something like this in a pretend grumpy voice, with our hands on our hips and shaking our fingers:
“I’m coming back down here in 10 minutes and this place better not be cleaned up or else I’ll have to tickle every one of you!”
You will probably hear giggles and little conspirators whispering “Let’s clean up and see what happens! Let’s make her throw a mommy tantrum!”
As you approach the area again say in another prentend grumpy voice “This place better not be cleaned up!” then when you enter the room, you pretend to be upset and do the thing you threatened (either pretend to have a mommy-tantrum or tickle them all or whatever in a light-hearted silly way)
This concept works really well on some kids and not on others. It also seems to work best with the younger crowd (under 6 or so, but depending on the child). I like using this because it makes cleaning up a game. It lets us have an opportunity to do work and be silly at the same time. They love pretending that they are disobeying and being naughty even though they know they’re really doing something good. For some reason, it works really well for our little ones!