C'mon guys. Don't you think the question might be deeper than just getting marks onto paper?
For whatever system you are trying to draw, identify where your utility consumers are located and the quantities of utilities consumed. Imagine how the piping might be run, and show your take-offs to the various consumers in the correct order. Now you'll have on a single page all your users, the total consumption of the utility, and the information needed for line sizing. (Firewater is a bit different since there's no normal consumption.) BTW, since your doing this for utility systems, we'd normally refer to these schematics as "Utility Flow Diagrams".