Things to work on to develop sidearm velocity:
1. A strong finger grip against the wall of the rim with your finger pads. Usually this is the index and middle finger pads. This can be done several ways and there are sites with pictures to help you here. The important thing is to use the pads directly into the wall and not the side of the fingers.
2. Use as quick of a whipping action as you can. Keep your arm loose for as long as you can.
3. The whipping action… Continue