So actual penile enhancement comes in 2 schools. Traditional PE and Angion.
Traditional PE comes in many forms but are divided into length and girth workouts, length is generally some form of prolonged stretching, girth is usually some form of pumping or clamping. Both are primarily centered around "plastic deformation" of the tunica. The problem with traditional PE is that its dangerous, has a high instance of erectile disfunction even if done right, and is a HUGE time sink. Your looking at between 20 minutes and multiple hours a day for years to gain more than an inch in any direction.
The Angion school is really new, been up and running for like 5 years, but is extremely safe. Its one of the absolute best things ive ever seen for erectile quality. It Might be primarily girth work as well. Angion focuses on using angiogenesis to push vascular density and erectile quality so high that your bodys only response is the expand to accommodate. Downside is that its a lifestyle, and outside of erectile quality gains it can take a while before you start seeing measurable results. However the increase in vascualrity, erectile function and erectile quality is amazing. If done properly you can get to the point of eliminating your refractory period, and you and your partner can feel your pulse throbbing during coitus.
The ultimate method most likely is some fusion of stretching and angion.
Now, dont go spreading this to /b/ you nerds, keep this a /D/ thing for now.