- Clothing - I think of layering for uphill activity (aerobic, lots of heat generated) and then breaks and skiing being relatively passive. My big "puffy" insulated jacket can be layered on top of my shell, and can often be my downhill jacket as well. My pants and jacket are "softshell" or "hardshell" depending on how wet the day will get: this is the Pacific Northwet, after all! I prefer to add long underwear if and only if the temperature stays below freezing (32°F/0°C) all day.
- Sun stuff - even when its overcast and snowing, I can get a sunburn. So in addition to packing sunscreen and lipstuff, I usually pack a ball cap. Goggles or glasses? I'm a glasses guy - especially for the uphill. If its snowing I'll bring a pair of goggles for the downhill.
- Gloves - bring at least two pairs: one pair that you think you'll wear all day. The second pair is in case the first pair gets too wet, or if I think the forecast is may get warmer or colder.
- Neck gaiters - better than any turtleneck. One lives in my pack year-round.
- Boots, skis (or splitboard!), poles, and skins - if you are borrowing, renting, or just made a new purchase: make sure that your boots fit your bindings, and your skins fit your skis!
- Avalanche transceiver/beacon, probe, and shovel - these three things are mandatory and must be in good repair. Avalanche transceivers must be less than 10 years old.
- Pack - I recommend a backcountry-specific pack with 30L volume (+/- 5L). An avalanche airbag pack is optional.
- Ski crampons - these are mandatory for the Pacific Northwest. I've had powder days in January where the old, established skin track into the valley was iced over first thing in the morning. Mine live in my pack, protecting my first aid and repair kits.
- Thermos - I find it easier to stay hydrated in the winter with warm stuff than with cold stuff, so I bring a thermos of tea or hot cider to get me through the day.
- Lunch stuff - depending on the tour, lunch is either a big break or snacks through the day.
- First aid - I pack a comprehensive first aid kit and two forms of emergency communication. All my guests need is a small first aid kit for blisters and any current medications.
- Phones, Go Pros, Cameras - absolutely!
- Change of clothes - depending on how long my drive is, I'll toss in a pack with a spare shirt, jeans, socks, maybe even a hat, gloves and jacket.
- Apres ski - consider sticking around to join me for a beer, wine or coffee.
- Gratuity - tipping for excellent service is always appreciated.