How do you put on a pouch jockstrap?

Some jockstraps have a pouch with an opening at top; the cup is supposed to go into the pouch through that opening. You wear the cup with the narrow end pointing down.

If your jockstrap doesn't have a pouch with an opening like that, but just has a simple pouch, wear the cup inside the pouch directly against your skin (again, narrow end down). If you have a lot of pubic hair, you might find that you prefer to trim a bit to prevent the cup from rubbing or pulling hair.