Easy Charaboms:
In a two player battle, you normally would lose your Charabom if you lost. However, turn off the power immediately before losing. Your opponent will get a free Charabom and you will not lose one. If done purposely, the person who wanted to give someone a copy of their Charabom would purposely lose, turning off before the final blow.

Hints:

Bomb shield:
When holding Invisible Vest, set a bomb and just as it explodes rapidly press A repeatedly. This will protect you. Be careful not to blow yourself up after the Vest wears off.