I want to masturbate but i am not sure my parents would approve, so I am doing it in secret

As a guy it's pretty simple as a rule, just take the foreskin and move it up and down over the head. 

as you get used to it you can start doing more interesting/exotic things

like involving Lube, Your ass and your testicles. Not to mention the thousands of techniques.

Play around a bit, experiment different speeds and strokes and you'll find whats right

You don't mention whether you are circumcised or not. If not, then the advice given above should suffice. (You might want to slip a tiny glob of hand cream between the foreskin and the head to increase the sensation.) If you are circumcised then you should put your hand directly onto the groove just below the 'helmet' and gently tickle until you locate the best spot. (A bit of hand cream would be even more useful than on an uncircumcised penis; its use can prevent possible soreness on the exposed head.) A few tries should bring you to the point of climax. Once you reach it you will be hooked :-)

P.S. How about posting here again to tell us how well our suggestions worked for you?

I am a mother and my advice for you is simple. if you are a girl you don't need approval from your parents and you should feel perfectly comfortable if you like to masturbate. if you are a boy your parents need to start when you turn age 13 and put you on medication I use for both my sons. it prevents the ability to ever get an erection experience an ejaculation, and what I wanted the most is preventing growth of the boys penis and causing it to get a lot smaller. no teen boy should be able to ever masturbate under any circumstance. this is not a boys privelege