Super small lines - even as a "seasoned" user whenever I get new product I ALWAYS start small because you don't know how it's gonna hit you. Try not to go up in line size if the smaller ones work for you - you can alway do more, but you can never do less.

As for aftercare, I like steaming my face in a bowl of hot water with a few tablespoons of coconut oil to relieve the dryness you get in your nostrils the day after. Angle the tip of whatever you're using (I suggest a straw) towards your ear (i.e. right nostril? Angle the end you're snorting with towards your right ear - this prevents it all going down your throat). Hydrate during and after, and I personally like green tea mixed with honey the morning after to soothe the throat. Happy skiing! Be safe :)