All it takes it a kid, a sheet of graph paper, and some crayons and you've got an awesome cross stitch pattern that's one of a kind, personal, and usually quite beautiful! And if you use the right (read: selective) set of crayons, picking the colors out from your thread stash should be a no brainer.
Graph paper isn't that big when you get down to interpreting it via Aida, and the crayons or markers they use are basic colors which you can then match with those random leftover skeins of floss you have in that drawer. So these are usually pretty easy and quick to stitch.
It's also really fun for kids to see their work reinterpreted in something as elegant and substantial as a cross stitch.
If you're feeling really adventurous, these are nice small stitches to experiment on if you're trying to get into framing your own work. You could even attach a magnet to the back and put it on the fridge, just to come full circle.