Sunscreen! Suncreen! Sunscreen! The tropical sun will burn the hide right off of a rhinoceros!!
Even my DH who never burns, lets me "grease him up"
I Pre did my tips in thank you cards before I left. That way you are not searching for the right amount of bills on the last night of the cruise. (you can always ajust them if you want!)
Take lots of quarters for laundary if you plan on washing any.
Go to the talk about "recommeneded" shopping places. They have a lot of good info.
Always ask about the drink of the day! Its cheaper!!
Join in as much games etc. as you can. It's just more fun!
At the art auction the first day, they give you free champagne!(You don't have to buy anything, or even stay for the whole thing!)
Relax and have fun!