>>88664
No expert, but from own experience can I attest that placing a warm/near hot tower on semi-erect (best about 65-75% erect) and doing kegels/dick curls result (in my case) in positive results.
Massaging your penis and the adjacent muscles gently (as in not masturbation but just treating your dick as any other muscle that you massage) is also good, especially while taking a hot (!) shower. I've found and released much tension this way and my dick is much more relaxed, compared to how shrivelled up it used to be while not erect.
And if you meditate then one good sitting position that works for penis gains is to place one foot over the other and placing the upper foot's heel on your pelvic floor, as to sit on the base of your penis (read it in a yoga/tantra book but don't have it anymore and can't find a pic that shows the position, but it's fairly easy to figure out).