Here’s how I do it:
Height: With the chain off, set it so it misses the big ring by 2mm or so, and make sure it’s straight.
Then screw the L screw right in, and the H screw out a lot. Fit the chain with the chain on the middle ring.
Now, while turning the cranks, with the rear mech in the middle of the cassette, unscrew the L screw until the chain drops onto the bottom ring – unscrew another half turn for luck.
On the shifter, unscrew the barrel adjuster 2-3 turns, fit the cable and pull as tight as possible before clamping into the mech.
Shift through the gears, adjusting the barrel adjuster as necessary to get it spot on.
Put it on the top gear at the back (smallest cog) and big ring, and screw the H screw in until it hits the mech stop (the mech moves a bit).
Done 😉