Just wondering if anyone knows any good heavy bag drills I can work on?

I have just bought a heavy bag so I can get some basic work in before going to a gym next month and have been browsing the web for some drills to try out. I have found one on youtube which is as follows, just wanted to know if anyone knows of any others which could benefit me? So far I have found one called the 30-30-30 drill but, obviously, need more than just this to keep me occupied:

- 30 seconds regular speeds punches.
- 30 second 'ride the bike'. Punch as fast as you can, lifting your knees up.
- 30 second knockout punches.

Repeat this twice. 1 minute rest.

I know it isn't much but it's a start.