Find a way to cheaply convert your US dollars into Jamaican dollars (Bank or Cambio) and pay for most things in Jamaican dollars.

ATM's charge a service charge which can vary but $5US or more per transaction is not unheard of. Your bank may charge a ATM fee AND a foreign transaction fee which can run from zero to 15%.

The exchange rate you get at a restaurant or bar will always be less then a bank or cambio. For example, beers on the beach can cost $150 to $400 Jamaican. You only have US dollars? They may charge you $1.50 to $4.00US. Might not seem like much, but with an exchange rate of $115 JA to $1US you just paid $230JA for a $200JA beer.

Total those savings and it is a easy 15% - 25% savings just in simple currency management.