Well, that's exactly it - I don't know! I'm really not trying to brag at all - I wish I was more somewhere in between than lasting forever all the time, but that's just the way it happens. I don't really have any pointers per se because that's just the way I'm built I guess. I'm an athletic/slim body type too, maybe that plays a roll.
The downsides for me are - that the girls I'm with are well and truly tired well before I'm done (and many are at an age where they take it personally as if they aren't attractive enough for me - and that's not the case at all, so believe me, it sucks), and when it comes time to get 'er done, in most cases I can only finish by hand. Should I really be complaining? Probably not at all. But I don't feel like running a marathon every time either.
I don't do anything out of the ordinary... just the usual zinc supplements.