Here are some of the things that my son and I have been training on the heavy bag for the past 5 months.. Some of these things we stay in front of the bag other's we move and use our footwork.
1. Stick (hit) and Move
2. Evade
3. Cut Angle
4. Engage and Disengage.
5. Close the gap
6. Strike with shoulder
7. Off Center strikes
8. Bump and Strike. - This is where you allow the bag to swing into you. so that you can recover and strike.
9. Stand your ground - This is where you allow the bag to swing into you, so that you can counter the impact, but not avoid it.
10. Grappling/ Clinch work.
11. Maintain Distance with footwork.
12. Maintain Distance with Arm.
13. Maintain Distance with Kicks
14. Maintain Distance with Punches.
15. Punch / Strike the gaps, (if your heavy bag can swing).
16. Step off center (with and without swinging bag)
I'm always taking a look at how I fight and try to translate it into a drill to use along with the foundational stuff that I do. It helps to keep things from being dull.
My personal thoughts on "Aiming punches" It think it's a must to have that type of accuracy. Well aim punches land. Carefully aimed punch helps to avoid the areas you don't want to hit, like the skull.
Aiming for the head vs Wild swing to the head. Which is most likely to land?
Aiming for the head vs Carefully aiming for the jaw. Which is most likely to result in hitting the skull?
Punch Accuracy and why it's important. Being focused doesn't have to look like a Martial Artist standing in a horse stance punching one punch at a time.