Equipment
Though many may choose to rent equipment, using your own equipment ensures that you'll have gear that you're familiar and comfortable with. This alone can greatly enhance the time you spend on the mountain. Depending upon baggage fees, it can also help you save some money. Remember to pack snowboard (with bindings) and boots. Be sure your board has a leash attached, if the resort you're traveling to requires one.
Outerwear and Accessories
Just as important as equipment are all the accessories and clothing for riding. Don't forget snowboard jacket, pants, gloves, hats, goggles and sunglasses. When possible, pack two of each item, so that you can allow for a full day to dry if needed.
Optional Accessories
Not everyone carries these, but they're worth considering: helmets, snowboard lock, wax and snowboard tools, face masks, scarves/neck protectors, boot/glove dryers and hand warmers. If you intend to ride back country, don't forget to pack avalanche gear.
Clothes
When it comes to clothes, you have a two-part mission: riding clothes and casual clothes. The former consists of your three-layer system, base layers and insulation like sweatshirts, fleeces and pants, in addition to the outerwear previously discussed. Consider how long you'll be staying, if you have access to a washer/dryer, and the predicted weather. Don't rely too much on long-term forecasts, as mountain weather can be fickle--pack on the warm side to be safe.
The latter is more like traditional vacation packing and really depends on where you're going and what you plan to do. Consider the type of restaurants and nightlife you'll be taking in and pack accordingly. Be sure to pack the right shoes for all occasions and consider that shoes may become waterlogged due to the snow on the ground, so extras wouldn't hurt. Also remember that you'll be riding, which means you'll constantly be hot, wet and sweaty--pack extras like additional socks, T-shirts and underwear.
Oft-Forgotten Extras
Here are a couple of items that won't make or break you, but they might cause you to smack yourself in the head if you forget: sunblock, MP3 player, hydration pack and extra goggle lenses (different light conditions).
Package Information
Don't forget any e-lift tickets, package confirmation information, registration, shuttle information, etc. In some cases, you may need to present printouts, so be sure that you have them in an accessible place (pocket or carry-on bag).
The Basics
Of course, don't forget all the regular vacation essentials like toothpaste, toothbrush, cologne, etc. Those are beyond the scope here, but you know what we're talking about.
