I would recommend (contrary to what some of you do) to remain on QNH for departure, until reaching TRANS ALT, and, during descent and approach, to remain on QNE/STD until reaching TRANS LVL for a few reasons.
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The reasons are simple.
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(1) If you have to come back for immediate landing...? Better have QNH preset, is it...?
(2) If ATC asks you to level-off "due to traffic" during your climb or descent...?
(3) If waypoints on the SID or STAR are published with QNH (or QNE) and is not what your altimeter shows...?
(4) If ATC calls you and requests "say passing ALT (or LVL)"... during your climb or descent...?
(5) If you have to play around with QFE in Russia or China...?
xxx
TRANS ALT is one thing clearly briefed for our departures (as well as the SID) rather than spending time "bla bla bla, we abort if... bla bla bla before V1 etc..." that we know well since years ago. Same for TRANS LVL during the approach briefing, and they are written on our "bug cards" for takeoff and landing.
xxx
To mention also, about the altimeter, is that we do not "short-out" the digits of the setting (like saying "987" for 29.87 inches, a habit of some of our Yankistan friends) and we say/readback the name in full of the setting units - such as HECTOPASCALS or INCHES (although this old fart still pronounces "hPa" as "millibars") - After all, our altimeters still have "mB" printed next to the Kollsman window in our old 747s.
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The only crewmember setting his altimeter "in advance" is our F/E, for management of cabin pressurization. He sets QNE before departure, and QNH at top of descent.
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Our 747 airplanes have an "extra altimeter" to the right of the captain's instruments (metric) - I preset that one to QNE prior to departure, and QNH at top of descent, as my "personal reminder" of proper QNH setting. That is the one I read to tell the passenger how high they will have to jump with their parachutes... (and they do not listen to the PA anyway).
xxx
Happy contrails