When I used to mow neighbor's yards as a kid, I'd do a crosshatch pattern that I'd rotate 45deg each week, orthagonal vs diagonal. Just doing one direction looks fine but a crosshatch looks even better, especially if they have thick, healthy grass. I wouldn't be as meticulous on the side and backyards, those would just get a single, slightly overlapping pass in whatever direction was convenient unless they had a really nice backyard, then I'd do extra there.

People like that golf course look and I'd get nice tips for doing it.