I use a couple techniques and systems, all of which keep me connected to the tree the entire time.
First, my system for setting my treestand. Using a linemans belt and harness, I climb the tree to the desired height. Then, I leave my linemans belt in place and connect my safety harness, back tether to the tree. I pull up my stand and set it. Before climbing on the stand, I keep my linemans belt connected below the platform and connect my tether above the tree stand seat. Then I disconnect my linemans belt and step on the stand. When I climb down after dark, I use the same process in reverse.
This yr I began using the safety line and prusik knot combination. I climb the tree the same way as listed above, Set my other safety line above the stand, then clip the prusik line into my tether on the back of my safety harness. Only then will I disconnect my additional tree harness tether from my back tether and unbuckle my linemans belt. I only have to do this process once because once I decend with the prusik knot and safety line, I only have to clip into the prusik knot and ascend, hunt and decend each time thereafter.