This one issue can cause failure
One of the common themes when it comes to advising for length training is that there are certain factors which can prevent length gains. One of the biggest is a failure to retract the foreskin or any interfering skin from the glans (penis head) before setting your device (or in the case of manual stretches, your grip).
Any interfering skin should be pulled (comfortably) towards the base first. What this does is to prevent the skin from taking the brunt of the tension, instead of the tunica and ligaments.
A more convenient method which can work well for device based OR manual training is to use a SILICONE SLEEVE. You'd pull back any excess skin on your penis towards the base before rolling the sleeve on to your penis. Once the sleeve is on, all should remain secure. The added benefit of the sleeve is that you'll also have padding and gripping for stretches.
Another tool you can use to restrain interfering skin is 3M MICROPORE TAPE. Pull back the skin and then tape the area from the skin forward to keep it from sliding while you're wearing the device. This works especially well with vacuum hangers.
For male enhancement training, developing the "kinesthetic" sense (the sense of FEEL) is vital. Doing what you can as far as preparation and performing exercises/movements correctly is important, but if you're net feeling that high degree of tissue expansion each time you train you may not be inducing growth.
