What you'll need: some white buttons and chenille stems.
You can cut chenille stem in at least 3 pieces and you'll have 3 sets of Oobi eye pupets. Instructions are easy enough: just put one side of chenille stem through both button holes and secure by twisting, then do the same with the other side of chenille stem. Show your kids how to do it, then let them do it themselves.
And now, play time!
For those, who would like an originals, there is a pack of 12 oobi puppets, or even larger ones you can use as a party favor: