Most people grip at the bottom of the Glans. That targets the tissue in between the bottom of the head and the main shaft of the penis. It really doesn't do shit and you could tug all day and not feel any burn or notice it in your tunica or ligaments. Yea it stretches your wee wee out, but it mostly stretches the head and the tissue connecting to the head, and thats not permanent. I've begun pulling all the skin on my dick back to the base of my penis and then gripping about halfway on my shaft and stretching outward. I remove the hand holding the skin at the base of my shaft of course so that I dont get stretching pains on the skin in my shaft because its usually pretty tight when I grab it and stretch outward. Doing this I feel an INTENSE stretch because I'm actually grabbing my Tunica and ligs firmly, and pulling them outwards. Not just playing with the jelly memory foam tissue in my penis.
Watch the base of your penis when you do this. You'll notice the 4 main ligaments at the top of your penis pop out and if you hold the stretch and put your fingers down there and gently massage you can feel the 'strings' that hold your penis being stretched firmly like an outpulled rope.
Also, using this same theory, grip a little tighter on your low erection jelgs and only go to about 1/2" away from your head and hold it clamped at the end and then slowly release it as your second hand repeats this motion. It constantly stresses the tunica and ligaments while the blood gets trapped almost like a halfway clamp in the center of your shaft. After 10-20 of these you'll notice the expansion in girth and also the extra stretching your doing to your tunica/ligs. Thats how I'll be doing my workouts from now on, and I'll try to cement some gains this way for a while. Either way I'll be getting in 20-30 minutes of this type of stretching and 200-400 of these type of Jelgs every day. It should help toughen my penis up and bring some of it out with good newbie gains from stretching my ligs and tunica for the first time in their life properly and keeping my chambers filled every 8-12 hours with some good jelging.
EDIT: You can also keep the hand down there in an OK grip like your about to Jelg while still holding the skin back if you have tough external skin on your penis and aren't worried about stretching pains or discomfort or rips. Keeping the hand down there gripped tightly at the base after your fully stretched out and feel the burn/stretch will also help stretch the ligaments a bit more, almost like a sock stretch.
Manual Work is serious shit, using all those toys that every ones been using produce SLOWER gains over time and can cause permanent disformations and curves and markings if the person using them is not very smart. Shit, just look at logs from 2004-2010. All the manual ones and the ones from way back when are 'Gained a shitload' with no Tools. All the new ones are 'I can't get this tool to work right and I'm not gaining shit.' So fuck the tool, use your hands. Play with your tool!