A known accurate gauge properly connected would be a great step one. A mechanical one where the sender is cuts way down on accuracy problems outside the motor. Ya know, like loose connections. My escalation process has generally gone like this:

Starting with a fresh bottom end, run 10w40 for the first 100,000 miles or so.

When bearing wear starts dropping the pressure, run 20w50 for the next 100,000 miles or so.

Add STP (if it still exists) to get the last miles.

Install a high volume oil pump and go back to 10/40.

The last new to me 360 had crap for oil pressure. When I finally got around to yanking the pan I found way too much of the pan gasket clogging the pick up.