After viewing a lot of the videos that get posted here, I think someone
should point out the necessity for a good experienced spotter.
There are subtle clues that reveal whether or not you have one in front of you.
They'll use standard terms like "Driver" or "Passenger" instead of saying stuff like "my way" "over there" and "right" or "left".
They'll also say it loud and clear and use hand signals. I also see videos where at least 1 other person is trying to spot.
I realize that on an easy trail this isn't such a big deal, but I've seen videos where everyone in the area is acting like a spotter.
I know they think they are helping, but they are just adding confusion to an already stressful situation. I've seen people volunteering to spot, including kids and wives with zero experience.
People have a natural desire to help, but when you have several people all giving commands things get hairy and an easy line can turn disastrous.
If you see me on the trail or at Jambo, when there's 10 people giving direction, you'll notice I ignore everyone but the 1 person I've identified as my spotter.
Incidentally I found this PDF file that shows the standard trail spotting hand signals. Someone might find this useful.