Hi,
Heres something I posted on another thread, but I think it suits your question.
heres a few techniques that worked for me:
Reflect on that feeling of disgust which drowns you after you PMO. Sitting there staring at the screen, lobotomy-eyed and drunk on dopamine. Then its all over. And what did you get out of it? Absolutely nothing. You feel like a pathetic sack of shit, right? Escpecially doing it in a public place - your head must be pretty fucked up. It was this sense of self-loathing that comes with PMO (in public,too, which I have done many times), that motivated me to never ever want to feel like that again.
Another technique I used was to write down all the things which PMO has fucked up in my life. Then a second list which details all of the things in my life that are bound to improve as a result of rebooting. The first list gave me tangible proof of the extent to which PMO has assaulted my life. The second list gave me the assurance that those things will never happen again. Keep both lists somewhere where you can see them constantly.
And finally, just the simple realization that there is absolutely nothing good that can come from PMO. Youve got nothing to lose and everything to gain.