For years I've lain on my back and stroked my lubed balls and cock downward. If I get close to a climax I pause before continuing and eventually end up cuming. I do this every morning before getting out of bed and every evening after going to bed (unless I got lucky that night). The results are more than satisfactory - my cock is longer and thicker and my balls hang lower. Plus, it's a great way to begin and end each day!