1. Start thinking about packing in advance. Make list of everything you intend to take with you before you pack. Use the list as a checklist when you pack to insure nothing gets left behind.
2. If you are traveling by plane and you are not checking your bag, buy 3 oz travel bottles for your toiletries or 3 oz travel size toiletries to make certain your toiletries meet the TSA requirements. Don't forget to put them in your quart-size Ziploc bag; a toiletry case of the same size will not suffice.
3. Wear the same outfit on the day you leave and the day you return home. This means you can wear your thickest sweater when you travel and not have to worry about fitting it into your luggage on the return trip home.
4. Pack clothes that mix-and-match easily.