I will admit that I normally don't wear a strap when climbing. I religously wear one while on stand though.

I have in the past, when sitting around the 20 foot mark and the tree I'm in isn't cooperating, used climbing gear to assist in safety. I placed safety straps at 5-6 foot intervals with carbines hooked to the same length straps. As I climb I just switch out the straps until I reach my destination!

Seemed like a lot of hastle and work but it made me feel better.