Wall serve is a great way for players at all levels to develop consistency with their serve, including good tosses and firm hand contact. Pick a spot on the wall about 8-9 feet high and serve from about 10 feet away. Once players get 10 good serves to the spot, have them back up one long step and repeat. Eventually, as players gain experience, they can back up as far as 30 feet from the wall.
Wall serve
The Bishop's School