Sagging is a "fashion" trend that doesn't seem to want to go away. Most of my male students wear their pants a size or two too large, so they rest on their hipbones instead of their waistline. How do I know this? They wear shirts that are normal length, so when they raise their arms you can see a portion of their boxers sticking up above their pants.
Since the whole point of sagging seems to be to get adults to roll their eyes, maybe if "old people" banded together and joined in with this fashion, the kids would decide it wasn't cool. Today I wore sagging pants.
From my observations, there are two parts to a successful sag: colorful boxer shorts and too-big pants. Since I don't have anything in my closet that meets the criteria, I was forced to be creative. My "boxers" were striped cotton pajama shorts. The outer layer was a pair of black knit ankle-length pants that I pulled down about eight inches so they were correct pant length. That made the pant's seat and the crotch come down proportionally, and showed the top of the shorts . I wore a white dress shirt that hung down and covered the exposed "undergarment". The stripes could be seen through the shirt if you looked hard, though, and when I raised my arms, the shirt rose up enough to show the top of the shorts.
My pants fit snugly around my hips. I definitely didn't have to worry about them falling down! Walking around was uncomfortable, and going up and down the stairs was a real challenge. The pants pocket, which normally sits at the hip on these pants, ended up being halfway down my thigh; it was very annoying when I put my cell phone in there.
I was glad when I got home and was able to swap out my "sags" for normal pants!