Here's a slightly challenging, but simple drill you can shoot to help you improve your accuracy and transitions. The Switch it Up Drill is great for live or dry fire practice and will help you get outside your comfort zone.
Here's how to shoot the drill.
From the holster or low ready:
String 1: Draw and fire two shots on 1-3 in ascending order
String 2: Draw and fire one shot in this order: 1-4-2-5-3-6
String 3: Draw and fire one shot in this order: 1-6-2-4-3-5