Pinch a lacrosse ball between an extended thumb and fingers away from your palm. Pound the ball repeated into the both sides of the mesh for a few minutes. Pour a small amount of warm water over the threads and get your pocket pounder; a specially designed mallet with a lacrosse ball head. Strike the net with the pounder on both sides until you can form a nice pocket. Stop here if you like the pocket you've formed or proceed with fabric softener for an even more pliable mesh.
Make it Pliable
Place your lacrosse stick upside-down into a bucket. Fill a bucket with just enough hot water to cover the mesh and mix in 1 cup of fabric softener. Let it sit for 20 minutes, pull the stick from the mixture and rinse under running water. The softener should give you a soft mesh with a pleasant smell ready to be formed into a pocket.