Here's a simple and fun drill you can shoot on the range or during a dryfire session. The Eight by Eight drill makes a great warmup drill and it will help you improve both your shot transition times and your reloads!
Before performing this drill during a dry fire session, make sure your gun is unloaded (double-check) and there is no ammunition in your magazines or anywhere in the room.
To shoot the drill:
From the holster, draw then fire 2 shots at each heart, reload, then fire 2 more shots at each heart