Our first tip is to set a time limit! You can do this the simple way by setting a timer. It's always a good idea to give warnings too, such as "only 5 more minutes!"
One way I did it in my classroom was with music or poetry. During transitions, for example, when we recited the monthly poem aloud as they cleaned up one task and came to the carpet, the students knew that they needed to be at the carpet by the time we finished the poem. Since they were familiar with the poem before this time they knew how long they had to make it there. It worked like a charm!
And another way I've seen it done in the classroom is with an end of the day clean-up song. I recommend a fun, silly song that you will all be happy to hear each day. The kids get familiar with the length of the song and when it's nearing the end so they'd better hurry!
Come back tomorrow for some more ideas to help your little ones accomplish a lot this summer. (We'll be showcasing some fun ideas like using tickets and a summer bingo!)