We tend to hold the penis near the base and stretch. This is where the Length Master gives the gripping strength and leverage to go against the two beastly ligaments. Brother SIM demonstrated on this in his videos on full stretch downward and angled backward to combat the ligaments. All all deal with these two beasts.
Agree with @oldandlively
You can also try weighthanging, before discovering MOS i used to progressively hang weights for 1 hour a day, maxing at 2,5 lbs for 2 months. I now have a very stretched ligaments and my erection had a visible curve because of that stretch, which is gone now.
Happy gains brother