Pack for the unexpected, but pack wisely and light. Remember, you have to carry it! Bring small quantities of toiletries. Bring those chargers. Take as little as possible through airport security. It will save you time and make you less likely to loose things. Bring your camera and important phone numbers.
Use a professional travel agent. They do not cost you anything but add experience and knowledge to your trip. They will work to fulfill your dreams and absorb all of the hassles and avoid the numerous pitfalls.
Look into trip insurance. Especially if you suffer from an existing condition or anticipate any future problems that could cause a cancellation or delay in your trip.
Always bring identification. A driver's license is adequate domestically, but a passport is best. Carry them on your person in a safe place.
Do all you can to stay well. Wash your hands frequently and take any prescribed medication. Avoid unsafe activity and travel with others. Eat healthy and drink lots of water. Nutrition and hydration keep you well.
Above all, get plenty of rest. Don't burn the candle at both ends. Play hard and then relax...