- Method 1: Any kind of flare. Seeing that all your planning, movements and orders are directly overseen by your adversary is enough to make you blunder. I use this all the time even when I am not ready to attack a place just to keep my opponent at bay.
- Method 2: Bombardment from far away in the map. Even if you do no significant damage, it's enough for your enemy to know that you are shooting at him without any hopes of him hitting you back. Stops working if enemy builds counter cannon.
- Method 3: Mines. Does not matter if they actually wipe a unit. The mere of thought of walking and losing men will make all but the foolhardly to retreat (and potentially come back with sweeper).
- Method 4: Planes. The weaker of the list, since they can be taken down kind of easily.
Any other ideas?
- Method 5: Saying "GG EZ" after the opponent has lost a sizable amount of his forces [donofsandiego].