Here's a simple and fun drill you can shoot on the range or during a dryfire session. The Cross Your Heart shooting drill is excellent for warming up, and it will help you improve both your shot transitions and accuracy!
To shoot the drill:
String 1: draw and fire two shots on 1, 4, and 5
String 2: draw and fire two shots on 2, 3, and 6
String 3: draw and fire One shot on 1 through 6 in order
String 4: draw and fire One shot on 1 through 6 in reverse order