Air-timing is a strategy involving using one's gun to blast the opponent high into the air, then firing your pods directly underneath them. They wiil then land on the pods, causing them to explode. Be careful - if your opponent gets a rebirth before they land or your pods miss, you will be vulnerable. Retreat quickly so as not to get caught in the following pod blast. It is highly risky, but effective if you can pull it off. Stationary pods are good for this.
The technique is rather limited to certain parts with certain blast types/effects due to its specific nature.