For me to feel safe i do a couple things.
Firstly, I leave my linemans rope tied in. Sometimes i will wrap it around the tree twice and since i have enough rope, let it have slack. If the tree is too big i'll put a screw in step on the side of the tree to help keep my linemans rope from falling too low.
Secondly, I use 1/2 rope and a beefier saddle. I did hunt with a latitude method which worked great, but a bigger beefier saddle and rope keep my heart rate low.
Third, I pick large(r) trees. I hate to admit this, but I have a fear of heights. I will never go to the grand canyon, i didn't like the top of the sears tower and so on. But i love hunting. So, the bigger the tree the better lol.