Travel must? DIY amenity kit. Grab a small cloth bag that'll fit in any purse or carry-on and pack it full of all your must-haves in any travel situation -- lip balm, extra cash, SHOUT wipes (trust us), wired headphones (in case your fancy Bluetooth ones die), Advil, mask, you name it. What's the one small thing you always make sure to bring with you on your trips?