Very often it is a folder with a lock and a pocket clip and I just clip it in right front pocket.
But . . . some times the knife is thick handled. I prefer thick handles like the stock Griptillian. The thick guys I carry in the ammo clip pouch shown here on the far left. Some folders I prefer with the pocket clip removed so they are also carried in this pouch. Two examples are the Cold Steel Ti Lite (vastly thinned FF blade) and the Spyderco Para Military both shown next to the pouch.
Then . . . I very much like the full size trappers. They have no clip and are too long to carry in my pants pocket because they go side ways in the bottom of the pocket and teeter across my leg. The trappers are too small for the ammo pouch and tend to flop around; might even fall out. So up until recently the best pouch I could find to carry them for easy access is the little black pouch shown with the top flap folded back and tucked behind the back and the metal belt clip.
I like metal belt clips; they allow me to clip the pouch to my belt without unthreading the belt, obviously, but also allow me to put my knife on the band of pants with no belt loops like the thick, old, sweat pants shown in the last photo and onto the edge of various bags I carry (walking, biking, working).
So I am not a fan of pouches that only have a belt loop and no clip.
Enter my latest knife pouch :
Ta-da ! ! ! the Boker Trapper pouch. Brown embossed leather. Quite nicely made / very even embossing and double stitched with heavy thread.
Shucks . . . it has only the danged belt loop . . . and I really like everything else about this pouch.
As Seven Of Nine always says "You Will Adapt". A tiny, tight, loop of paracord and a key ring hook and . . . .
Who knows . . . this could be good. Very comfortable so far / doesn't dig my side when I sit down like the first clip-over-the-top-of-the-pants pouch (the black one with the folded back flap) .
Time will tell.
The pouch was a bit stiff when new. I wanted to form the leather to the knife and since the knife I carry in it is C75 carbon steel (easily rusted) I didn't want to wrap the knife in plastic and soak the pouch in water (I was pretty sure the plastic would tear and the knife would get messed up. I put the knife in the pouch and carried it for a couple of days under my shirt on a big loop of paracord around my neck. The humidity and the heat seemed to do the trick well enough. It is not a nice tight custom fit but the knife fits well and has the right amount of hold on the knife. It is pretty dry here and not getting hot during the day so the knife did not rust at all from sweat.