After any season, throw a pizza party, with the rule that no food is consumed until every lego has been put in its place. Not only does it get things cleaned up, everyone gets to enjoy pizza.
If your lego kids aren't too involved with other things, a mini challenge would be a great thing. Or even better, why not continue to work on this years robot? Get it to work, and find out what went wrong. If there are other teams in your area, maybe get together and have an off season event of some sort.
Going into the next season, where your team is all fired up to make it to states, make sure that even if you have to grin and bear the hard workfor most of the meeting have a little fun at the end, or have a snacktime in the middle. Snack times are always fun.
