Sub-metering water

I’m new here and have searched the forum for info I’m looking for but haven’t seen it so I’ll try! I’ve read your recommendations for sub-metering, but we don’t understand how to do it. We have only 23 lots on 2 acres. I see companies that will do it for you and bill the residents, but mostly we just want to figure out who the water wasters are and get the problem solved. Is it fairly inexpensive to install these meters ourselves? I’d love some do-it-yourself instructions!