1. THE FEAR TACTIC. Picture how embarrassed you would be if somebody walked in on you! You certainly wouldn't want THAT to happen, would you?
2. I LOVE MY GRAMMA! If you wouldn't do it in front of your grandma, you shouldn't do it at all.
3. THE PARENTAL APPROACH. How would you feel if you saw your parents masturbating? Wouldn't you be disgusted (I know I would...)? Now you're doing the same thing. Kinda nasty, huh?
4. CHRISTIANITY COMPLEX- if you are a Christian, you surely know that God is always watching you. Would he be pleased with what you are doing to your body? Even if you are not doing it using pornography, He does not want you masturbating to those thoughts. Pray for help in overcoming these sexual feelings.
5. (my favorite!) THE ADHD/ ABOUT FACE- "hmm.... maybe I should go mastur- HEY, IS THAT CHOCOLATE? I'M SUDDENLY HUNGRY AND NOT THINKING ABOUT SEX AT ALL!"
-Hope I helped. :)