When I want to 'blow a nut' really quick I have found this technique very helpful. I suppose one could vary the process to extend the time between onset and eruption, but I usually like to get things done quickly so I can get back to whatever I was doing before the need to 'squeeze the weasel' came over me.
Get a vibrator, preferably one with a rather pointed tip. Pull out the one-eyed wonder worm and pull the skin back. Use the vibrator to stimulate around the glans area. I have found that the underside is particularly sensitive. Experiment with it to find out what suits you best. It can be done with or without lube.
In my experience, I can shoot a load completely limp in less than a minute.
I have also applied the vibe to other areas in the genital region with satisfying results. The base of the cock (underneath with slight pressure) and perianal area are good places.
If you are really adventuresome try stimulating the prostate with a vibe! TALK ABOUT ELECTRIC!! If you have a girlfriend (or other friend) it can be even better. A lot of folks think that the 'back door' is exit only. WRONG!! There are a lot of nerve endings there just waiting to be stimulated.
I am glad I was able to contribute here.
Happy Jacking to all.