We try to minimize the number of brass parts we use as much as possible (in favor of push-to-connect fittings) to reduce weight. We usually only use a single brass tee, and use that to mount the high-pressure gauge right next to the regulated gauge. The pressure switch goes into one of the accumulator ends. Somewhere on the high pressure side we use a push to connect tee, and mount the manual vent valve right next to the main breaker.
We also mount everything with zip ties, as this photo from our unfinished 2007 robot shows.
