'Root infested hell track' or 'technical bliss'... individual perceptions affect the way we each view different terrain. When you discover a new track that looks way scary but obviously has been ridden by others, then one day you too should be able to ride it with confidence. The question is, "how to get to this other universe?"
Confidence is not to be confused with commitment. Once confident in your abilities, it's vital to back yourself and commit to riding that tricky section. Dithering, losing the flow or your balance at the top of a drop off can be embarrassing- often painful. Increased confidence is gained through improving your skills, typically from tuition and hanging with better riders than yourself. Add to that, regular time on your bike, repeating tricky moves, finding a 'local trail' to dial in, and the right bike that is set-up properly (any excuse to raid the piggy bank). Get the right mix and the only way is up. Or down.
A confident rider immediately sees the 'line' - the smoothest, most efficient route through a gnarly section. There's often an obvious, most ridden line, but that isn't necessarily the best line. You're probably being led astray if the 'well worn line' feels clumsy or slow, requiring you to ride around obstacles away from the natural fall of the trail.
It may feel reassuring to fix your gaze at the front wheel, steering it through and around obstacles, but the confident rider looks ahead to pick the best line. Otherwise you risk getting incrementally led down an unrideable section of the garden path. The faster you go, the further ahead you need to look. Rely on your peripheral vision to be aware of stuff going on around you and monitor what's happening under your front wheel - tyres only need a narrow gap or a few centimetres to sneak through.
Of course, the best line through a corner or over a drop-off depends on your bike handling skills. Here are some 'instant soup' tips to lift your skills and let you choose a better line:
Now confident, let's revisit commitment. A half-hearted attempt, or riding with one foot un-clipped is guaranteed to negate any gains from your increased skill base. It's okay to get a little out of your depth and occasionally crash, just don't do it all the time. You'll be amazed at what you can pull off in the thrill of the moment.
You can be committed without pushing yourself to 100% all the time. The top, very fast riders often hold a little in reserve for the unexpected. So, know your limits and choose the time and place to push them. Backcountry riding and shared-use trails like the Heaphy or Old Ghost Road prescribe an element of restraint - holding back on blind corners and sections with high exposure. Flying along a one-way pump track at your local mtb theme park is the time to let it hang out, 100%. The right mix of confidence and commitment will make you a situational master ... not afraid to select your own lines, and not the one who wrecks their bike or body on a group outing. You'll move into the 'flow', the Zen of mountain biking, where everything is calm, in control, the adrenalin is on tap, and you can't put a wheel wrong.