It's simple. The first rule is to remember that you are a guest in someone else's country. Unlike a certain presidential candidate who goes by the name of Mitt, don't come off as an expert in their culture. Try not to criticize a country that has spent the better part of seven years preparing for a world party like the Olympics. Be gracious, even if you don't mean it.
Try not to hold a fundraiser in a country on a day that coincides with a religious holiday that commemorates numerous Jewish tragedies. Especially if that country is Israel. Take a look at a calendar before you pack your suitcase and check if your plans coincide with a national 24 hour fast. Also if you're a guest, it's permissible to give your hosts a gift, a small token of friendship. Giving a host country carte blanche to dictate America's foreign policy and the ability to drag us into another middle eastern war is a bit over the top. A menorah or an etching would have sufficed.
You have to take into consideration that there is a possibility that they won't be able to speak English. Whenever I travel abroad, I always remember a few key words or phrases to show that I'm making the effort to speak the language. Trust me, this works. A lot of people do speak English and will be glad to help you if you if you treat them with respect by trying to communicate in their own language.
In Italy, I've discovered that you can get along very well with three words: Graze (Thank you), ‘scuse (Excuse me) and prego (Please). In fact if you start each conversation with ‘scuse, the Italian will recognize by your accent that you don't speak Italian, stop you from making a fool of yourself and tell you that they speak English.
When in France, remember this simple sentence: "Je suis desole, mais je ne parle pas francais" which means, "I'm so sorry that I don't speak French." Your mangled pronunciation will so entertain your hosts that they will laugh and then confess that they speak perfect English. My first time in Paris and I was lost near the Paris Opera House. I approached a gendarmes (Policeman) and in my best-broken French used the magic phrase. He motioned for me to stop and said "I speak English" and we had a nice conversation about directions back to the Rue de Rivoli. About halfway through the instructions, a woman wearing a Texas t-shirt pushed me aside and barked at the officer "How do you get to Napoleon's tomb?" in her loveliest Texas accent. The gendarmes shook his head and replied "No par le vous ingles." The tactful Texan muttered an obscenity and stormed off. I looked at the offer and shrugged. He shrugged too and continued to give me my directions in perfect English.
Travel is fun and exciting. It's exhilarating to go to new places and experience different cultures. Except if you're Mitt Romney. Then it's best just to go visit your money in all those foreign banks. You don't have to interact with foreigners and your bank account will always translate into English.