Here is my tip...buy a bottle of rum cream on your first day and enjoy it in just about everything during your stay LOL...j/k (I mean I do that, but just kidding about it being my tip) LOL

Here is my actual tip:
I avoid using my credit cards / debit cards for any purchases (unless it is my final bill at the hotel or something). Instead I use cash for everything, preferably in Js (Jamaican currency). I carry a couple hundred with me and then I go to the ATM and get more as needed. Time Square has just added a new ATM from Scotia so it will give you either US or Js. I also bring with me some small US bills like $1s and $5s to have for tipping. But no matter how you use your money, Call your bank or credit card company prior to leaving and give them your travel dates and location. Many banks nowadays have international blocks so you dont want to get over there and not be able to use your card and then be stuck with no money. Its just a quick call and they will remove the block during your travel time.

Have fun!