Edging is about self control, and that is something that has to exercised. It gets stronger the longer you exercise, but only if you don't give up. When I edge, I go very slowly and as soon as I get the sensation that I'm about to orgasm, I stop. I wait until the sensation goes away, and then I start again.
You never let yourself go all the way. You don't "reward yourself" for being a good boy and not cumming, that's the point of edging. If you can only last 5 minutes without cumming, then that's your session. You put your dick away and suffer the blueballs. Then you do it again the next day, and the next day, and so on.
You allow yourself to orgasm only when you are free of the need to reach it. The delayed gratification is what will blow your mind.