Generally, if one of my children tells me he or she is bored, I find a closet that needs cleaning out or a toilet that needs scrubbing, so I seldom hear that complaint.
I will often recognize times, though, when an organized activity can prevent whining or bickering when the kidlets aren't finding anything constructive to do on their own.
Here is one activity everyone loves, including Mom. I write a list of items for the kids to pack into a scene and they spend half an hour busily packing it all in. The kids can then take turns making the list for the others to draw.
Here are a few we have done before.
2 lions, 1 zebra, 2 antelope, 2 baboons, 2 trees, 1 warthog, 1 warthog den, 4 meerkats, 1 cheetah, 1 giraffe, 1 river, 3 hippos, 3 termite mounds, 2 hyenas, 1 ostrich.
1 house, 1 sidewalk, 4 trees, 12 birds, 1 cat, 3 kids, 8 flowers, 5 clouds, 2 dogs, 1hill, 1 car, 1 bike.
1 barn, 1 cat, 1 dog, 1 big pond, 3 pigs, 2 cows, 3 horses, 5 kids, 5 ducks, 1 mommy, 1 daddy, 1 sky, 8 flowers, 1 apple tree, 1 garden, 1 hoe, 1 rake.
That's what Works For Me when the kids are bored.