Right away there was a problem. They had connected the elastic with big plastic "clips" (my little one called them "cameras" because they were rectangular with a round silver grommet, or "lens", in the center). When I asked her to put her shoes on, she would tell me "Not the one with the cameras!" I think the little clips rubbed on her foot and hurt her.
So I did what any reasonable person would do. I cut them off. This left us with a flip flop with no elastic strap. We tried to use them like that, but 2 year olds have a really hard time walking in shoes with no back strap.
Then it hit me. Rubber bands!
I love my baby's chunky little feet.
Find rubber band that are not too small or tight. Hopefully you have two of the same size. (mine were not the same color, but that didn't bother me)
Put the rubber band around the base of the flip flop straps.
When you put them on, make sure that their toes are on TOP of the rubber band in the front so that the band won't slip off. Then just pull up the band in the back onto their heel.
Obviously, I wouldn't CHOOSE to do this as a permanent shoe. But in a pinch, it works like a charm. I think I'll start carrying rubber bands in my purse, just in case.