I rarely adjust mine.
For A/C, I aim the left and two center vents at my face; the right vent stays closed. Temps are 71 or 72 for the driver and 75 for the passenger (who isn't there). The fan speed stays at the lowest setting unless I've just gotten into the car and it's been sitting in the sun.
I can't remember as well what I do in the winter. That's an old-guy problem, not a first-world problem.
In that season I only drive on dry, sunny days while wearing layers of warm clothing and a beanie. As in the summer, the temp settings are focused on the driver and the passenger side is set much differently.
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2017 M240i: 23.8K, 28.9 mpg, MT, Sunroof Delete, 3,432#, EB, Leather, Driving Assistance Package, Heated Front Seats | Sold: E12 530i, E24 M635CSi, E39 520i, E30 325is, E36 M3 (2)
TC Kline Coilovers; H&R Front Bar; Wavetrac; Al Subframe Bushings; 18X9/9½ ARC-8s; 255/35-18 PS4S (4); Dinan Elite V2 & CAI; MPerf Orange BBK; Schroth Quick Fit Pro;
GTechniq Crystal Serum Ultra Ceramic; Suntek PPF