I discovered early on with my daughter that I needed to talk to her before hand... She would get upset when it was time to leave, I'd give a little pop on the booty and in the car we would go. While she was still upset I explained to her that if that happens again it will be a long time before we go anywhere! The next time we went somewhere I reminded her of our "conversation" and the consequences of her acting up. About 20 before it was time to go I always let her know that it's almost time to go or clean up... then remind her again at about 10-5 minutes... "If you want to swing again, or slide now's the time to do it" And then when times up it's up! She may give me a frowny face... I remind her of just not coming at all, she may be a little pouty but thats it. I have also found if it's a friend that she is playing with setting up the next play date with her helps too...