Here's a simple drill you can shoot at the range or during a dry fire session. This drill will help you with three skills — done regularly, it can improve your transitions, accuracy, and speed up your reloads.
To shoot the drill:
From the holster or low ready:
String 1: Fire one shot in this order: 1-2-3-4-5-6
String 2: Fire one shot in this order: 6-5-4-3-2-1
String 3: Fire one shot on 1-3-5, then fire one shot on 2-4-6
If you are dry firing, make sure to follow all the safety protocols! Before performing any dry fire drills, make sure that your gun is unloaded (double check) and make sure your magazines are empty and there is no ammo anywhere in the room where you're practicing.