Butterick 6288 is a pattern from the late 70s or very early 80s.
I used a bit of leftover cotton interlock and cut the waistline a little lower than the original pattern.
As you can see, I prefer to use casing for the elastic. I think that it gives me greater control over the fit – especially at the leg openings. (When I took the photo, I hadn’t inserted the elastic into the leg openings.)
These have sewn up so quickly that I’m inclined to make them by the dozen!