I have developed a technique using slip knots around my cock and balls.
I use small diameter rope, around 1/4' thick, otherwise it would be too thin and damage your cock and balls. You need a piece of rope about 18' long. The slip knot is a quick release knot, so if it is too tight around you cock it can be released quickly.
So I make a slip knot and pull it fairly tight around my balls and cock. It makes my cock very hard and raises my balls a bit higher and closer to my cock. It is a wonderful feeling. Every now and again I release the knot so as not to damage my cock.
I often add another slip knot around the underside of my cock head glans and pull it tight. With the loose end of the rope I then pull my cock from side to side... it's a great feeling just doing that instead of rubbing my cock up and down like a normal wank.
So I have one knot around my balls and cock at the base, and another around the cock head glans. I can wank for an hour or so, before I have to release a huge load of cum. It is wonderful.