Dom1:
First think about how the audience is going tk hear your sounds — that is why 92 db in front of amp or monitor makes sense. Else Fletcher Munson effect ( see wikipedia) when you dial in presets.
I do it both about a yard away when I measure. Once I know the volume range on my equipment to gett to 92 db output, I don’t have to kill my ears...you do it for awhile then you know what works and doesn’t.
I also have a monitor about 12 feet away to simulate being on stage aa a check on the sound. Loud enough? Balanced, not too much bass, too much treble, good strong mids to punch through?
Lots of in ear types, but they should replay sound like monitors do.