When using the type that slides together, it's pretty simple. Stand the stick against the tree, attach the straps as you go, using the harness so your hands are free.

What I do with the kind that don't fit together(I don't use lone wolf, but a similar design) I bought a long rope, and tied buckles/carrabiners/etc. along the length of the rope far enough so the sticks wont touch.(noise) I secure each section to the rope, with the stand at the bottom, climbing, pulling the rope to the next section, climbing, all the way to the desired height and finally mounting the treestand in only one trip up the tree. Rope would be tied off somewhere on my harness, usually at my backside to keep it away from my hands. Bow rope would be tied off there as well.

I don't know if it qualifies as 'safe', or if it is even the best way to go, but I like it.