Bring five basic outfits that you can mix-and-match, as well as five or six pairs of underwear and socks. Ensure the clothing is weather-appropriate for the destination; if it's a cool climate, bring one warm sweater or jacket, a pair of wool socks, and outwear like gloves and a scarf. If it's a warm spot, bring a swimsuit and light, breathable coverups. If formal wear is required, choose an outfit that won't get easily wrinkled during transit. Don't forget something to wear to bed, as well as no more than two pairs of shoes, depending on the climate and nature of the trip.
For a shorter trip like this, travel-sized toiletries, including shampoo, conditioner, soap, mouthwash and face wash will do fine. Remember to pack a toothbrush and toothpaste, as well as any makeup and hair products. Remember sunscreen if travelling to a sunny destination. If travelling by plane, ensure that the liquids in the carry-on bag don't exceed the airport specifications (three-ounce containers in a single plastic bag).
Remember to pack any chargers for cell phones, mp3 players and electric razors, as well as any accessories or cords for laptop computers. If travelling to a foreign country, check to see if a plug adaptor is necessary for these items; adaptor kits with all the plugs for most international destinations are available at drug stores and travel accessory shops.
If travelling by air, be sure to have your boarding pass and passport readily available. Also, print out and carry a copy of hotel confirmations, car rental agreements, and confirmations of any other pre-booked excursions for the trip. It also doesn't hurt to bring a book or magazine for down time during travel.