Never lose a battle
When playing a battle and you are on your last unit, make it move as far as it will go for your first turn and click
fast anywhere for your second turn. While they are moving, your first unit moved will get a #1 mark in its area. Click it, and it will move again. Repeat clicking to move to an enemy unit and kill it. Keep in mind that if your first unit dies, you cannot use this trick in that battle.