I found that when I replaced my 115 mm stem for a shorter stem (100) my turning radius was tighter and more controlled. This helps with switchbacks, especially when climbing. Also, riser bars instead of flat bars will help you out on descents. Fine tune your fork for your weight and check your rebound and damping. Tire pressure...trail conditions and the type of trail tell me what to inflate to. But I never go over 40 pounds. Also, take a look at Kenda Nevegals, a wider more aggressive tire that will truly help you on descending and bite in good for climbing. I've ridden Pisgah, Bent Creek, Tsali, Dupont, and some trails around Ashville and its tough riding, very technical and I had smaller Continental Explorer tires that had great rolling ability, nice and light, but I wish I had my bad Nevegals back then. Keep your clips looser, but not too loose that you pop out of them when lifting up with your feet. Learn to get off your saddle and behind it and hold on to your handlebars. When you go over logs or roots, you hold on and you tell the bike where its going. I can't tell you how many times I've crashed because the bars got away from my grip. Learn to stick your opposite knee slightly out when going around tight turns to balance yourself. Take a section of trail at a time and clean it, then move on, when you ride try and do one new thing each time and be happy with that victory. Momentum is your friend, you will crash more going slowly then if you had the speed to roll over the obstacle. Going over logs and coming to a stop, if you can't balance or track stand you are going down, and remember if its a big log set, pedal over it! Don't think you can float over everything, sometimes you need to pedal and dig in. Speed and body english will get you over the logs or rocks, and there is nothing wrong with dabbing your foot down to push you over something. You will get better each time you ride. Whew....so much more, but I just wanted to get out the stuff I learned early on. And...it helps to ride with someone who is really good, so you can follow their lines.