The first thing you need to do is choose whether you are going to put the leash on your wrist or on your bicep. If you’re putting it on the wrist, place it just above the joint and tighten it just so it can’t slip over your hand.
If you want to put it on the bicep, slide it above the elbow, bend your arm and tighten it. It shouldn’t press too hard when you’re paddling or moving your hand.