Something to consider is taking a few sec/min break. Stretch your legs. Go get the mail. Unload the dishwasher. Wiggle like a snake. Jump up and down like "tigger" (by son loves anything POOH). Pretend to be in a circus and walk on your tip toes.
For longer breaks I love educational movies & games too! Freestyle Art is a lifesaver. Just letting them have their pick of fabric scraps, cardboard, sewing notations, and other odds and ends. It's peaceful but creative. Sometimes they just tool around with the items other times they make something like a cloak or doll necklace.
I have used a few ideas from Homeschool Shares Activity Cards in the workboxables section.
The link is below. Scroll all the way down to the bottom of the page. The name of the PDF is
Activity Cards by Candace Crabtree.
http://www.homeschoolshare.com/workbox.phpYou could pick out a few to just "do" with your kids or you could cut out a bunch of them, mix them up in a jar or paperbag and let them pick out a card to "do". It creates surprise as well as interaction which my kids thrive on

Can't wait to hear more ideas
