This is an exercise I do from time to time when I am trying to get a better flaccid hang and a more pronounced separation of the extreme under base of my penis and where my scrotum attaches. It is easy and very effective.
DLD's Extreme Scrotum Stretch
This exercise is to be done in a standing position
In a completely flaccid state grab your scrotum right above the testicles with a standard OK grip. Now stretch them up toward your belly button. Now, reach behind your legs grabbing your penis by the glans and stretching it up toward the top of your crack. Stretch to your max with both hands and hold this position for 30 seconds.