540 wrap around a stem, pole gives fall-arrest. I'm amazed more people don't use it. Having confidence that I'm save make my more confident, climb faster, and get more done. A choked climb-line goes a long way. Why would a new climber not take that protection? When slipping down a pole you still have huge step gaffs ready to sink into a leg, even if you're not getting beat up by the trunk.
Find a removal tree, set a climb line up high, have someone "tail" (tend your slack), and climb up AND down the tree for practice.
If I have a small sub on the back of the trunk or 540-wrap providing fall-arrest, I'll climb to a negative lanyard angle, and advance my rope higher than I would otherwise. As with rock climbing, sometimes the best position is found by climbing a few inches higher than you wanted to stop. Knock the little sub off from above, after resetting your rope.