It takes practice and patience. I have edged for years. When I was younger it was not unheard of for me to edge upwards to an hour.
Now I am able to edge to the PONR many times during an edging session. There are times during edging sessions I experience chills and my body shutters somewhat. I simply pause, hold a strong Kegel until the urge to finish passes. This only takes a few seconds.
This morning during the session, I too leaked a few drops of fluid. It was definitely semen. After the urge to finish passed I was able to go hard at it for quite a while.
I utilize a Fleshlight sometimes during my edging sessions. The feelings which result are very intense.
BTW, may I ask how old you are. Sometimes being younger affects the ability to hold off cumming.
Stats:
08-12-2014 BPEL 8.875, EGMS 6.6, EGB 7.25, EW 2.101, EV 30.331, FL 6.75, FG 5.6, Glans Girth 6.5p