Ditto...I use clippers on my head about every 5 days...have had a mustache since 1976.. My hair on top started to check out about the same time. I was 19 at the time...When I was a kid with a flat top I used butch wax, and when I first grew a beard right after high school I used moustash wax. Both products were sticky and involved too much fussing to be worth the bother. Untill I ran out of hair I followed Shaver's dictum. I stopped using hair products some time around 1970.
Currently, every two or three days I use barber's clippers to cut my remaining hair as short as possile. I then feather the sides of my somewhat short beard. As my hair is white I don't have the dark dot problem that frequently accompanies shaven heads. I use barber's scissors to tidy up the lower edge of my relatively full moustash and generally neaten things up.
I shave my neck at the sides and back, and under my chin, daily.
When I travel I find barber shops and generally get satisfactory results.