Originally Posted by Riverwild
I would add that you want to have some nylon webbing tied off to different lengths. You can wrap these around trees and rocks, double them up to provide the anchor to your haul system.
It's not a bad idea to incrementally replace your webbing.
Start with a long, new piece. Pretie it, but don't load it. If you find yourself needing a custom length, it's easier to tie one that hasn't been fully loaded.
If you get a wear spot in one of your older slings, cut it and tie that hunk of webbing into a smaller loop.