When packing clothes for a trip, lay out what you think you'll need for the duration of the vacation, then put half of it back in the closet. Two outfits per day is plenty; one for daytime sightseeing and excursions, and one for dinner and dancing or clubbing at night. Go with a single color scheme so you can vary your wardrobe without packing a lot of accessories. One suit with different colored shirts is enough for a man unless traveling on business. Women will find they get more fashion mileage out of an interchangeable combination of skirts and blouses than a suitcase full of dresses. Above all, know the weather at your destination, not your point of origin. You might be leaving a winter wonderland, but Aruba enjoys tropical weather year-round. Pack accordingly, remembering to fold clothes tightly along seams and creases to reduce wrinkles. You can always steam out your clothes on hangars in the hotel bathroom by running the shower blazing hot for a few minutes.
Pack shoes and heavy items on the bottom of the bag to keep the weight distributed.
The first items you need at your destination should be the last things you pack--that way they are close at hand near the top of your bag.
Experienced travelers who have dealt with lost luggage also know it is good to pack at least one outfit in the luggage of your spouse, partner or traveling companion and vice versa. That way, everyone has at least one clean change of clothes if the airline loses a bag.
You'll need a passport for virtually all international travel from the United States, plus a secure place to stash your passport, cash and traveler's checks. A zippered money belt that fits under clothing or around your neck is the best option for keeping these items safe.
Prescription medications should go in your carry-on bag, along with a doctor's note or packed in the labeled pharmacy bottles with your name on them. Save yourself a hassle at security checkpoints: never carry unmarked pharmaceuticals in a bag.
Personal toiletries are subject to ever-changing airline security rules, so check in advance of your trip how many liquids you can pack in a carry-on bag. A small tube of toothpaste, toothbrush, deodorant, a spool of dental floss, a bar of soap and a comb or hairbrush should take care of most travelers for at least two weeks. Avoid packing items like mouthwash, which add unnecessary weight to your luggage and can be easily purchased at your destination. Transfer a small quantity of your favorite cologne or perfume to a small, sealed plastic bottle so you'll have some fragrance without risking the loss or breakage of a bottle of expensive scent. Pack your toiletries in resealable plastic bags.
If you carry a camera, bring extra film or a memory card if shooting digital. Spare batteries, too. Any personal electrical or electronic devices such as a hairdryer, MP3 player, iPod or laptop will require electrical adapters when traveling in foreign countries. Find out the voltage situation where you're headed and bring transformer adapters for your electronic gear. Most kits come with an assortment of adapters to handle any power outlet you are likely to encounter.
Smart travelers stow their electronic gadgets in a carry-on bag and keep it close at hand. For business travellers, a padded briefcase is essential for a laptop, peripherals like a cordless mouse and headphones, and the power adapter.
Don't forget a couple of paperback books and a magazine or two for the plane ride and rainy days, as well as a phrase book to improve communication in countries where you are not fluent in the language.