On any stage in Skirmish mode, get into a confrontation with your enemy, then turn and warp all your ships to the corner of the map. If done correctly the enemy ships will attempt to follow and warp directly into the corner of the map and become stuck. Depending on which ship it is, the enemy will not be able to fire back at your fleet. Some enemy ships will only be able to use their rear phasers and torpedoes. However, this trick rarely works with the Borg.