Hi Alex.
Harness on except above 10000ft no turbulence and no visit to the toilet of one of the two CM.
Those on most of our 737 are especially tight and unconmfortable, so I often cheat a bit and take them off even before 10000ft, but not in descent.
I don't accept the harness to be removed just after landing, as you might still collide with something... but only after the parking brake is set.
Take off: PF TO, PNF LEGS
Autopilot ON: PF LEGS, PNF PROG
Cruise the same, but of course we visit various different pages, above all FIX before descent to check position by temporarily turning to Manual the navaids, DES, INIT REF....
APP: PF INIT REF or FIX, PNF PROG 3 for the wind components.
Ciao