They typically pool the tips in Camp Carnival so one envelope is sufficient. It's hard to say what the proper amount to tip is, because I think it would depend on the type of service they provided, the amount of time you utilized their services, but for us, it's usually between $20 and $50. A few bottles of water or soda ought to be no problem. I usually bring along a few of those single serving bottles of wine to consume in our cabin, it was really nice on the balcony, its not a problem!