Masturbation techniques?

I'm a horny 13 year old girl, obviously I'm too young to have a vibrator or anything like that. That seems to be what I need though because I'm not as sensitive down there as I used to be. Anyways, does anybody have any easy, rather quiet (I mean I need to do this at night when everyone is asleep so yano, nothing, for example, in the shower) masturbation tips?