What does pressure give you? Or is this for something like a well? I know for my house, with city water, I don't really care...the incoming pressure from the city is well over the 90PSI that I set my house to. At least that is what I think I set it to. I'd have to check again.
Essentially, I set it to that at my closest branch. It just happened to be a hose spigot. So, every other faucet/valve/etc. should be less than that.
--Dan