Couple things off the top of my head from experience: * Running out of food is lame * Carrying way more food than you really needed is lame * Forgetting mean

Couple things off the top of my head from experience: * Running out of food is lame * Carrying way more food than you really needed is lame * Forgetting means to light a stove is really lame * Little critters will chew through whatever to get to your food, so keep it outside your tent (hang it high off a tree) * (Mountaineering) Exposed skin will be scorched by sun reflected off the snow * Separate your "keep me dry" layer from your "keep me warm" layer, don't go cheap * You need to drink more water than you think you do * Unless you have guaranteed means/opportunity to dry yourself/clothing, avoid getting wet (avoid cotton, jeans) * Everyone should know the route, if there's a fork or ambiguity in the trail, everyone needs to be together * Have a backup means of filtering/purifying water * Always tell someone where you're going and when they should expect you back * Check the weather and recent trip reports