I masturbate at least once everyday for no less then an hour. I've used the handle of a screw driver for over a year and I have to say it's amazing.
I've recently tried something different. I start off gently rubbing my clit and getting myself wet. Then I pump the screw driver handle into me for about 20 minutes. Then when I am really really horny, I take a bit of minty toothpaste and rub it on my clit. Almost instantly it starts to tingle and I don't even have to keep rubbing it for myself to cum. All I do is keep pumping the screw driver in and out and I explode with the most amazing orgasm.
Another little trick I know is this: A lot of times I get horny at school if I see a guy I like or whatever, or sometimes I even get horny at people's house's. I found a really good way to get myself off. I take a book with me. Hard-cover always. I start off with making my pussy pulsate and then I make it look like I'm just holding the book on my lap, but I stick the corner into my clit area and press down every few seconds. It's great, and gets me off anywhere. I have worked hard at learning not to scream or breathe to loudly when I cum, so if you do, this is not something you should attempt in public at first. A little trick is to pant your way through. I started off panting, and now I can be near silent.