This is a good strategy for the game Pocket Tanks. I found this out by playing around in The Target Practice part of the game. If you do not have the game, people using a PC can get it at Pocket Tanks for PC. If you use a Mac, you can get it at Pocket Tanks for Mac
All you need for this is a computer (which you must have if you are reading this), and the game Pocket Tanks on your computer. You only need the free DEMO version of the game but it makes no difference if you have the full (expanded) version.