The ins and outs...
You: On all fours, arms stretched out in front of you. Lean on your hands to keep your balance. Keep your head down to avoid arching your back. Imagine you're shaped like a coffee table!
Him: On his knees behind you, he holds your hips firmly and thrusts inside you, delivering an orgasm with a capital O!
Why is it so good? Also referred to as doggy style, this is one of the basics of Kama Sutra. The vagina is tipped in such a way that the penis enters at the optimal angle for reaching your G spot.
A good time to try it: When you're feeling wild! Grrr...
Tip: Don't try this position out on a carpet or rough floor. You'll end up with serious carpet burn! Guide his hand towards your clitoris for maximum pleasure, too.