4. KEEP IT CLEAN, YA FILTHY ANIMAL.
Got extended travel plans? Do yourself a favor and keep the inside of your suitcase clean between destinations. The number one nasty captain? Your shoes. From the park, to the mountains, to the beach, those puppies have been picking up whatever dirty crud has been left behind. When it comes time to throw them back in your bag, grab the shower cap from your hotel room and wrap it around 'em. Problem solved.