One of the best tips I've learned, and I got it here from someone else, is that things always go better if deal with locals like they are going to become a friend. Taking a genuine interest in your waitress or a customs official or whoever usually leads to very nice experiences. Go in focused only on the task at hand and in a rush (type A or NYC attitude and representing the ugly American) and you might very well find the true meaning of the term "Island Time". Starting with a nice "hello, how are you today" goes a lot further than "hey, we want to order...". I've gone places years later and somehow they still remember me - when in Rome!