u have to know how bright u want your photo and u set matrix, or
spot metering on your camera.
its common sense : if u know that the background is bright and u
wanna capture someone's face that's hiding in the shadow, u flip to
spot metering and aim at the face.
good angle, the lower the more dramatic.
sharp, just keep it in focus and sharpen in photoshop.
composition and timing, its up to your own skill already, read 1
million books ain't gonna help.
/me scribbles down notes... 
