RE: How do you practice??
I think treestand hunters should devote a healthy portion of their time practicing treestand shots, but not ALL their time. Why devote your entire practice routine toward a goal of making yourself a treestand specialist and a one dimensional hunter?
Lots of guys do all their practicing in the heat and light winds of late summer, then their accuracy goes astray when they put on extra clothes for the cooler fall temps in those cold front winds. Practice in all conditions and in as many situations as you can create so you can be flexible and adaptable in the woods.
Whenever possible, I take advantage of a foggy, drizzly day to go shooting. If I don't get one, I go so far as to take a spray bottle full of water and spritz my bow down. Maybe I'm a little extreme, but I need to know if damp weather is going to cause problems that don't crop up in dry conditions.