A straight tree is most important for safety reasons. I've climbe a crooked tree once. Once was enough for me to realize that it's not apractice to get into the habit of.

I look for a tree that'll get me 18-22' up the tree with preferable a pine or spruce tree behind or partialy in front of me. I find these types of tree will offer the most cover through out the entire season.

If you plan accordingly you can cut deer runs in by the trees you picked out early in the season. From past experience I've learned if you cut it they will run.