Learn to pace yourself and remember to schedule easy rides and rest days into your calendar. Technical difficulty is rated on a scale of 1 to 5, with 1 being the easiest and 5 the hardest. Requires basic bike-handling skills. Most slickrock is rated level 4. Again, most of the rides in this book cover varied terrain, with an ever-changing degree of technical difficulty.
Some trails run smooth with only occasional obstacles, and other trails are seemingly all obstacle.
The path of least resistance, or line, is where you find it. In general, most obstacles are more challenging if you encounter them while climbing than while descending. Realize, too, that different riders have different strengths and weaknesses. Some folks can scramble over logs and boulders without a grunt, but they crash head over heels on every switchback turn. Some fly off the steepest slopes and others freeze.