Cut both ends off a shampoo bottle that is slightly larger than your cock. Put two socks into the bottle. The stocks should be one inside the other and should be thick enough to fill up the bottle. Cut the toes off the socks.
Step 2: Put a latex glove in the bottle
Wrap the open ends of the socks around the outside of the bottle and tape them. (Duct tape works best). Now do the same thing with a long latex glove. Keep the fingers of the gloves intact except for one that you can use for releasing pressure and providing suction, cut a hole in that one. Insert a butt plug you-know-where for extra thrills.
Step 3: Lube up and go
Use your favorite lube and go at it. If the bottle is too big, use more socks to take up room and provide extra padding.