So true, Roy, age is the nemesis for us as well as the bikes.
I keep a couple of old wooden dining chairs in the garage, and a low stool, so for most jobs I can sit at the right height. Plus, find I spend too much time losing tools or putting them down out of reach so have taken to always using a metal tray, usually place it on the second chair, and trying to get in the habit of putting tools nuts & bolts etc down on the tray so everything is visible and in reach. Save a lot of bending down and a lot of getting up to fetch tools.