To be honest, like many of you...i made quick gains in the beginning and then they slowed to a stop. I couldnt figure out why. Thats when i did some research into the nature of the tunica. The tunica consists of ultra tough interwoven collagen bundles that do not break very easily. When you first start pe ing, the tunica has never experienced pressure beyond that of an erection...it is not prepared for the stresses being placed upon it. However, its a fact that the body has a way of adapting to new stessors . So after a while, the intensity that you've used becomes ineffective. A lot of people talk about switching up routines/strategies and all of that, but what it all boils down to is that you have to increase the intensity ( not necessarily repetitions) and maintain that intensity over a longer period of time.
In my workout sessions, i would keep the penis clamped at the highest pressure possible for as long as I could without the penis going numb. The longer I maintained this very high pressure the more the tunica would expand...were talking an expansion rate of the tunica of 1/8 of an inch every 5 minutes that this pressure was maintained!! So what i'd do is keep maximum pressure on the tunica for a span of about 15 minutes and do this 3 or 4 times. Circumference increased from 6 inches around to 8 inches around after one session.
I think a lot of people aren't making gains, simply because they're not stretching the tunica to the point where it needs to be stretched before it actually tears ( I did some research on this and basically when you get past the yielding point of the collagen which makes up the tunica and ligaments in your body, the covalent bonds between the atoms and molecules of the collagen break causing permanent "plastic" deformation.