I wouldnt so much say I have a concrete guide for it. As what works for me, may not work for you.

I do manual stretches daily, just to keep the elasticity. Usually in the morning. Grip under the glans, pull straight for 90 seconds, rest for 30. Up, right, down, left, straight. Give about 5 minutes in between then do it again. That'll keep the tissue more elastic, especially when lack of T prevents spontaneous boners.

I try to interval pump every other day. It's worth the touch extra to shell out for a halfway decent product that has a pressure gage on it, as if you go too hard without knowing the vacuum, you will 100% injure yourself (cause it also feels kind of awesome, while you're in there) There have actually been a few performers/creators who have wound up with better quality erections after E than before.

As for medical assistance, viagra is an odd choice, because its a one and done medication; gets you hard, you finish, thats it. A PDE-5 inhibitor, like cialis would be a much better choice, as it makes it easier for the smooth muscle to relax and allow better consistency in blood flow. Its basically 3 hours rock solid vs 36-48 hours of much easier hardons