This is really great advice for folks just getting into more technical riding. It took me a few solid years of riding 3-4 times per week at BC before I was able to conquer most of the features. My approach during the developmental phase was to go out with the primary objective of having fun and staying fit. Secondarily, I would focus on one or two features per ride that I thought I should be capable of tackling. Initially when I couldn't clear something the first try, I was trying 3-4 times and just getting frustrated. Eventually I adopted the approach of never trying a particular feature more than two times per ride. As my confidence grew and I started clearing more and more features each ride, I adopted the approach of never trying a particular feature more than once per ride, and if I failed, I would focus my next ride on making sure I attacked those same features that tripped me up the last ride.
Speaking of BC features, there is one that I love that gets little attention or discussion on this thread. It is the alternate drop when coming E-W on Picnic at the point where you would otherwise turn left towards PicnicX. It's a steep, rockface that requires some finesse braking and cornering, without which you'd be slamming into the adjacent rockface. You also need to maintain enough momentum to get you up the incline at the other end of the horseshoe. Not sure if it has a name, but it's a great feature.