Soft straps for wrapping around trees for rigging should be the polypropelene type, not nylon. Don't use tie-down straps or climbing gear. These things are often confused. On Lewis wenches, never use a larger powerhead than recommended by the manufacturer. There were several examples where larger straps, shackles and blocks were actually rated for lighter loads than smaller items.
Insulated cable is required for delivering loads by helicopter.
Climbing spurs are used for redwoods and large fir, not good for use on hardwoods. Swedish climbing ladders are a safe and easy way to climb trees for setting blocks. When moving heavy objects, look at both mechanical advantage and friction reduction. Reducing friction also helps minimize resource damage. We had a lot of fun busting up some big rock in the Peppermill's parking lot, and generated a little bit of concern from the security people there.