QNH is normally used for terrain avoidance, airspace avoidance, airfield procedures, and so-on within 25nm of the airfield in question.
RPS is for long routes where changing setting constantly isn't useful, and is the best case for a cluster of QNHs. It is conservative for terrain avoidance, but non-conservative for airspace, and potentially incorrect for flying an instrument approach procedure.
I use QFE, for preference, when flying visually in the circuit, but not for an IAP or terrain avoidance.
So, typical good practice is QNH on departure, RPS en-route (with a bit of fat to ensure you don't foul up and climb into the bottom edge of any airspace), then depending upon preference and procedure, QFE or QNH on arrival.
Not many countries use QFE, but it's useful and convenient in the UK.
G