Using a power pole saw to prune a water oak (aka "Spotted Oak") (Quercus nigra)
Photo courtesy of the Olympia-Granby Mill Village Museum Facebook page - https://www.facebook.com/OlympiaGranbyMuseum/
You get good at dangling from a tree and aiming your rigging line to secure limbs you're about to trim.
Removing a big tree in the middle of houses, next to a power line, and over other valuable property is a meticulous job. A trained arborist and tree care specialist has the experience to know each step to take to insure the safe removal of the tree. One has to choose which limbs to cut in what order, and with each step the team of tree care professionals have to be alert and aware of their surroundings. Everyone should be on the same page, and safety is always the number one priority.