LOL, ummm if i had that answer my pics wouldnt be so bad....
To be honest I do the shotgun approach... I take a dozen pics and usually out of that I get one or two I think look nice.
My best advice, get a camera that has manual mode and just start taking pics...
the really good people (amp takes beautiful studio type shots) know how to use lighting.... im still a babbling baby in that area
But for that read a blog called the strobist.... amazing, but ya gotta get some basic equipment to do their assignments
Im learning though, here is crop from one I recently took with my vintage Jupiter 9
If you look carefully in her eyes, you can see I used two lighting sources... in what is callend the rembrant config.
The key light is a soft box to the right of the camera at about a 45 degree angle to the model and an umbrealla as a fill light just to left of the camera.
The fill light was on about 1/8th power and the key light was on about 1/2 power.
Exposure was set using a 18% gray target
(a very textbook setup/shot )
http://strobist.blogspot.com/2006/03/lighting-101.html
Edit: add link
HTH's
Av