You need some novelty handcuffs, a rubber or tennis ball. Any type of ball that can be drilled should work. It also needs to be big enough to be cuffed.
Step 1: Drill a hole.
Drill a hole to hold the thumb. In my case, it required a 3/4 inch hole. But, if you are making these for someone else, then you need to use the size drill to fit their thumb.
Be careful not to drill all the way through the ball. If the tip of the thumb can be stuck out the other side, it can be used for texting.