Before Philip Bovenkamp wrote his champion cybug Leo, nobody thought much about it at all, although I do remember my Reaper getting trounced by Ladybug on a map where the walls were only one block thick. Reaper would be on one side of the wall, and Ladybug would fire a missile into the other side of the wall, killing Reaper with the splash damage. Even then, I thought I was unlucky, and didn't see the oppertunities that this opened up.
Anyway, I digress. Leo would set up a nest of mines around himself, and fire a missile into them whenever anybody came near. This started the ball rolling, and soon all the top cybugs used this technique to their advantage.
Another common trick happened during a discharge-energy fight. The bug that was losing the battle would back away, lay a mine in front of itself and blast it with a missile to finish off the enemy.