Ski trips are some of travel's most gear-heavy getaways-which is exactly why so many travelers get packing wrong. Between bulky jackets, old equipment, and items that never leave the hotel room, overpacking happens often. To help cut through the clutter (and avoid mid-trip emergencies), we asked ski resort pros from the U.S., Canada, Italy, and beyond to share what actually belongs in your suitcase-and what you're better off leaving at home.