Booster...
I strongly recommend staying away from the optional fight with Booster.  All you have to do is make sure the Snifits don't find you; it ends up being faster and you'll also get the Amulet.  However, if you're either determined to get into as many fights as possible in the game or you just never developed those hide-and-seek skills, use your logic!  Heal when you have to, attack when you can.  I have faith in you.