1. A list of phone numbers and addresses you'll need. This is a huge time and stress saver, especially if you pre-program them into your phone and/or GPS and print out a copy.
2. All travel documents, proofs of payment, itineraries, tickets, and pre-planning information you may have found.
3. The right amount and style of socks, undergarments and accessories. Nothing's more annoying than women having a halter top but no strapless bra, or all of your workout clothes but not enough clean socks to accompany them.
4. Electronic converters for international travel - all those electronics you packed won't do you any good when you realize there's nowhere to plug them in.
5. Chargers - For the phone, camera, and anything else whose battery life has potential to burn out in the midst of your trip.
Photo: flickr.com/photos/kathycsus/ / CC BY 2.0
For more vacation advice, visit RTM's Travel Advice & Tips section.