Make a list of items you'll need to pack. Organize them by layers: base layer, midlayer, outerwear. Don't forget to include small items like socks, gloves and hats and any packable accessories like gaiters. You should take your own boots with you if possible, even if you plan to rent the rest of the gear at your destination, so don't forget to add those to the list. They'll count as one item of carry-on luggage.