Tipping: It should be about 10% to 15% of your bill. The average tip for a porter at the airport is 1 US dollar, and the same goes for housekeeping and gas station workers. You can also tip ushers, washroom attendants, and others with change from your pocket. Most people do not tip taxi drivers but do tip tour guides.
Safety: Most of the drug violence is located near the borders of Mexico and the United States, but reports have surfaced recently about violence encroaching on the tourist trade. The best advice is to be mindful of where you are and who you’re with. Make copies of your passport and tickets in case you lose them, and they are stolen, and you need documentation.
Health: It should go without saying, but do not drink the water.
Money: The exchange rate for using credit cards is often better than exchanging cash for pesos. When your credit card is charged more than likely it will be charged by Mexican pesos instead of the US dollar. You can find ATM machines in Cancun; you will also usually receive pesos instead of US dollars.