How many things can you hang in one visit?

Shelves, mirrors, art and curtains

Hung level, spaced right and anchored for what's going on them.

Into studs, or into anchors rated well over the weight. Never the plastic plugs that came in the box.

A gallery wall gets laid out with paper templates on the wall first, so you can move things around before a single nail goes in.

As many as you have. Price it as a list.