Most people take far too much. A few changes of clothes, basic toiletries, a camera, and a few other items are all you need. Very do-able if you obey the previous tip. Be organized . The more footwork you can do ahead of time, the more you can relax on the trip.
Stuff happens .
Flights get delayed, hotels lose reservations, it rains. Be prepared in advance and have a backup plan in place. Plan an Official PreVacation Night sometime the week before the trip. Get take-out, soak in a bubble bath, listen to relaxing music, eat bonbons, use aromatherapy. Most important, don't do any vacation-related errands or planning.