Avoiding injury has two major reasons. One is general penile health, you need your penis working properly. After all, you use it every day when you use the bathroom. The second reason is because injury creates long-setbacks. If you injure yourself, you cannot continue to do penis stretching training, which adds on a 1-3 months of delay because you need to focus on recovery, instead.
You can try bringing a toy into your bedroom if you want to improve your penis size. You can use a vibrator on your bed and you will surely feel better. Similarly, other sex toys can do the same effects for you. Actually, this is among the best tips on how to make your penis bigger naturally at home, so you should not look down, but try bringing a toy into your bedroom.
Lengthening the penis. The most common procedure is to cut the ligament that connects the penis to the pelvic bone. This allows a little more of the shaft -- on average less than an inch -- to become visible outside the body. It's not really lengthening the penis so much as revealing more of what's usually hidden. To prevent the ligament from reattaching, a guy would need weights or stretching devices daily for about six months.