Pack shirts, sweaters and pants or skirts that coordinate with one another and that are easy to handwash. Pick one color scheme --such as black or brown -- and make sure everything goes with it. Go for garments that do not wrinkle easily. Take pants or skirts that will be appropriate for more formal occasions, such as the theater.
Layer your clothes, especially if you are packing for both hot and cold weather. Sneakers and jackets take up the most amount of room, so always wear them on traveling days.
Take about half the underwear and socks you need and plan on handwashing these necessities during the trip.
Bring travel-size toiletries and a small container of laundry detergent
Roll and stuff your clothes to maximize the space in your carry-on. Leave a bit of room for souvenirs.
Take one backpack or one large purse that matches with everything to use for your daytrips. Store your camera, journal, wallet and other items you'll need every day in this bag.