Shelf, mirror and picture hanging in Pickering runs from brand new drywall to walls that are fifty years old. The Seaton homes north of the 407 are barely lived in, with nothing on the walls yet. Down in Bay Ridges and West Shore the houses date from the 1960s and 1970s and have been through several owners already.
Both get the same treatment. I find out what is behind the surface, choose the anchor for the weight it has to carry, and set everything level before it takes any load at all.