No one's mentioned the scientific research aspect yet. Ideally, one should use private practice as a means to discovering techniques that will elevate the performance level in game situations.
Most guys would probably want to achieve one or more of the following feats, if they are, at present, unable to so do:
1) Have his penis reach its maximum girth, and thus, it's maximum volume, but not necessarily its maximum hardness, initially.
2) Have his penis be more sensitive, but less volatile. That way, it feels better, and for a longer time.
3) Have the ability to maintain a plateau speed indefinitely: Self explanatory.
4) To have full mental control of when his orgasm will occur, AND know which aspect of his current behavior he needs to change, to make that come about.
5) Extend the length of time, and the intensity, of both the pre and post ejaculative periods.
6) Achieve the rare male multiple orgasm, (two shots, minutes apart, from the same erection).
I discovered a technique that's reliable for 1) - 5). Number 6) has been achieved, but not in a statistically significant number of occurrences, and the effect of extraneous variables has yet to be codified.
Fortunately for everyone involved, I understand the tremendous responsibility of possessing such knowledge, but not disseminating it. If my method was to fall into the wrong hands, so to speak, it could destroy this Industry, within a generation.
Consider the following: If every guy had full control over how long he could last, a lot of guys would book an hour, and fuck for an hour. The ladies would have to drastically reduce their schedules, to account for the recovery time required between appointments. This would require most Escorts to raise their donation amount, perhaps beyond the budget of the average working stiff, after their second tryst with someone who knows the secret.
From there, the number of Escorts in the mid price range would rapidly decline, either because they would upgrade their description to courtsan, or they would seek alternative employment. If I guy found a hidden gem, he would keep it to himself; he'd be a fool not to. There would be no more new girl reviews, unless they were bad ones. The Industry would be filled with ladies you can't afford, and girls you don't want to fuck, just like in your real life, which is why you hobby.
And everyone would blame me.