What advice would you give to someone trying skiing and/or snowboarding for the first time?

I can guarantee that in your first couple of days of skiing, the best thing you'll learn is - "How to get up after falling, and get going again" !! You will slip and fall anyway as a beginner, and that's how your mind and body will teach itself a sense of balance. So, don't be afraid to fall ! Take professional lessons from an instructor for sure. If you can find time to enroll for a short course, nothing like it. A good instructor can teach you more skiing in one day, than all the answers on Quora :) For a new person, skiing may be hard on knees and back. If you're in a good fitness state, you will enjoy the ski time rather than struggle through it. Make sure, your knees and back are strong. Do appropriate exercises as a long term preparation. And before your daily ski session too, warm-up and stretch.

1) Bend your knees - you will be much more stable (and much more confident) 2) Make sure your boots fit well and are tied tight - This is one of the biggest issues I see when I teach. It is much harder to move your board or skis when your feet are moving around inside.

Whether you chose skiing or snowboarding, you should definitely take a beginner lesson(s) to avoid injuries.  The choice between skiing and snowboarding is a matter of personal preference, however, if you are only planning a short, one time trip, you should try skiing.  It is actually easier to learn how to ski than snowboard.  Interestingly, it is easier to get to the intermediate level as a skier than snowboarder, but harder for skiers to get to the advanced level.

The best advice is surely taking a lesson or seeking out instruction. One can only research so much about how to ski or snowboard. Not only will a professional instructor provide proper techniques, it is highly recommended to avoid injury and learn about the proper safety protocol. This can be a very dangerous sport and learning how to participate correctly is an important thing and can add to the enjoyment of it. Trying to ski or snowboard without a lesson could lead to injury of not only the participant but also others sharing the slopes. I would also suggest a helmet for first-timers as well

I would try skiing first, but that's really your choice to make.  The main thing is to take lessons, group at first and then private as you improve. Don't get obsessed about skiing black diamond runs, you will make more progress by honing your technique on easier runs - especially as a beginner.  So stay in your comfort zone regardless of peer pressure, but work hard on improving your technique.

You're going to fall over. Do it in powder, not on the iron-hard bunny hill where 5 other beginners will immediately be unable to miss you. 23 is still young. Old guy beginners need to be more careful; they really can break stuff (though I read that banging yourself around helps prevent bone loss). Skiing is supposed to be fun. It is fun, but if you have bruises on bruises the first day and feel like you'll never understand the drill sergeant of an instructor it might not seem that way. People broke their legs 50 years ago before modern bindings were invented. It's still possible, but you need to work at it. Don't be talked into things clearly beyond your skill level - acrobatics, for instance. Don't follow people better or more foolhardy than yourself off cliffs. A good instructor will push you to your limits, but not beyond. You don't need back-to-back lessons, a few private lessons with lots of practice time off between may be more enjoyable.

The bunny hill may be fine for skiing, but when learning to snowboard, you need a steeper incline! Find a quiet spot on an easy slope to practice stopping. Get really comfortable coming to a stop facing downhill, uphill, downhill, uphill. I wasted a lot of time and energy with an instructor on the bunny hill. The whole experience was terribly frustrating. It was painful, too! The slight incline meant that I fell constantly because my lower edge kept catching on downhill snow. With a slightly steeper slope, balancing can be very natural. On a nearly flat surface, control is much harder. Until I moved to the steeper slopes, I was like Bambi on ice, with my instructor, like Thumper, not getting why I didn't get it.

Always  keep your hands in a fist when learning to snowboard. When you fall  backward punch the snow and sit on your butt. A broken wrist is the  most common beginner injury when learning to snowboard. Learning to push (skate) on your snowboard  is very important because  you need this skill to get to and from the  lift. Force yourself to push (skate) from behind your heel edge, taking  short steps, as this will make your snowboard glide much better. http://www.powderpakoz.com/

This is the easiest Quora question to answer ever...swallow any pride, spend the money, and get a lesson from a professional, before you even rent your equipment.  Don't even consider getting on the slopes.  Ask for an instructor who is "good with beginners"; I always suggest that if you are a man/boy, ask for a male instructor; if you are a woman/girl, as for a female.  Falling all day on your arse will make you hate what you can easily love.  Honestly half a day of lessons will take you where you need to go.  If you can do the whole day of lessons, do it.