I have several holsters but sometimes I use this simple fast way for carry. I call it the OSS loop. Going to the bathroom is easy and your hand is ontop of your gun.
Works with any gun in any position along your belt. With full size auto's bending over and sitting for long periods can be uncomfortable if carried in the front. Small revolvers and small auto's are not a problem. The G-17 pictured disappears under a tee shirt.