It’s hard to put up signs in a building that are useful to new people.
In order to put up useful signs, you have to know where everything is *and* understand what’s confusing to people who don’t already know.
The problem is, once you know where things are, it tends to feel obvious. It’s hard to remember what’s confusing and what needs a sign to be clear.
One way around this is to get a new person to help you to put up the signs. People who haven’t been around long enough to know where everything is can help you to figure out where signs are needed.
Another way is to keep a list of things that people ask for help finding.
Short version: If you want to put up useful signs, seek out ways to listen to people who need signs.