My approach to training a new climber is a bit different. Getting a climber into the tree where the fun is with the least effort is the best way to get them hooked on climbing. I've seen new climbers get discouraged by other ascent methods and be worn out when the get to the top. There is plenty of time in a climbing career to learn ALL of the ascent methods.
Some sort of ground-anchor SRT is the easiest way into a tree. A friction hitch or ascender, with a backup then using a Pantin and the climber is off to the canopy!
Once in the tree they lanyard in and change over to a DdRT setup.
The climber would have already had experience on a DdRT system in small trees already. All of the changeovers would have been taught, drilled and demo'd on the ground. I'm nearby, likely, right there next to them in the tree so that I can coach the switch-over.
Saving calories is the core of my approach. We get paid to have incidental exercise, no need to go to the gym for a workout.
later, perfecting a footlock comes back into play.