Hi, I’ve seen people say that snapping your wrist helps the yoyo spin longer. What is this? Thanks, Skyler. 
Basically right before you release the yoyo.
when you are at the step where your forearm is flying down towards the ground you will quickly move your hand downward, thus snapping your wrist. Also you can go to kwos.com for good pics.
It’s pretty much just flicking your wrist, it’s more wrist than arm when it comes to sleepers