All of us develop drills to improve player shooting. Here are three that I've used to work on shooting form, targeting, and quickness.
1) Form (two options)
a. Chair shooting. Place a folding chair at the low block and have player shoot from a seated position. Players who "shoot from the chest" will struggle to elevate their shot.
b. Kneeling shooting. Player kneels at the block and shoots five from each side. This similarly discourages shooting out of the chest.
2) Targeting. Player stands facing the side of the basket and visually finds a spot on the side and shoots repeatedly at that target. When you miss, you usually end up chasing the basketball.
3) Lateral quickness. There are a number of drills used, including a pound dribble from a standing position into a shot. I prefer to have the player in a 'dynamic' position (e.g. off the catch), who must close their eyes after the catch, make a 'rip' move (laterally) with crossover step with eyes closed and then open eyes after the move to shoot as quickly as possible. The players must be able to complete the move WITHOUT looking at the ball.