I'm watching it right now, he brings up a good point early on about noticing terrain changes and turning around and studying the trail behind you.
I've always done this every time i passed a section where the trail was faint, or after emerging into an open area from a wooded or bush area, when
dropping into washes,or when the trail crosses slickrock or riverbeds.
Another technique i use is scratching notes on the ground with my staff, as well as building small cairns, or hanging low growing plant branches up
high on an oak branch, basically leaving something out of place. Wedging an agave stalk in some rocks upside down makes a distinctive flag when it
comes to marking a tributary wash. Recently I was descending down a wash that led down into the main canyon, and when i got to the main wash, which
is several hundred feet wide, the 50-75' wash that i had just emerged from was nearly invisible from the main wash. I took a break, built a cairn,
explored the area a bit, dug for water, left tracks, and practiced walking back into and out of the path that i'd need to take from a few hundred
yards up the wash, looking at all the distinguishing features, and what trees grow where and noting it, i knew i'd have no problem knowing exactly
how to get back into the wash and up to the main ridgeline and saddle that drops into my canyon.
Many times whether on bike or on foot, following my own tracks and sign has got me reoriented.
Enjoy!