Keep control of the cannons to use to slowly chip away at an enemy base. Cannons will continuously fire at an opponent's base, as long as you have control over them. If you can control all three, they will charge up briefly before hitting your opponent for 10 points of damage. Try to make this happen as often as possible. Another way to deal damage is to lead your units directly into an enemy base. If they can make it in all the way, they deal damage directly to your opponent. The large and more costly the unit, the more damage they will inflict. When using this strategy, concentrate on one lane. Send enough units into the other lanes to keep them from being completely overrun, but always focus on a single central lane.