Never trust the airlines to get your painstakingly customized and perfectly broken-in ski boots to your destination, or you risk spending vacation in rental-boot hell. Carry on boots in a pack that also includes toiletries, socks and underwear (one pair each), hat, gloves, base layers, ski jacket (if you're not wearing it), ski pants and anything else you'll need to go skiing while the airline supposedly searches for your lost luggage.