The sunlight and shadows playing on Alana gave a fantastic feel to this shoot; and, lets face it, she has a fantastic pair of tits for the light to play on!
For the technically minded amongst you this type of shot is very simple providing you get the exposure right

The camera meter is going to see the window and the bright sunlight and try and balance this with the dark shadows and produce a mid grey image with burnt out highlights. This is going to be at its worst if you are using digital or transparency film as these media have very little latitude. (Ability to record detail in over exposed highlights and under exposed shadows). Colour negative and black and white films have a wider latitude but would still struggle to cope.

You have to make a choice as a photographer. Do you want to save the highlights and let the shadow block up or vice versa. With digital take a meter reading from the highlight and set this as your base exposure. You may be able to stretch this a little by adding 1/2 a stop to the exposure as I did here.

To get a little more detail into the shadows you must add more light.
To produce the picture of Alana bent over the chair, which I thought may make a book cover, I positioned a silver reflector to bounce some of the window light back onto Alana's bottom. This illuminated this area a bit more as I knew this was what the publisher would want to see.

You could also use a fill in flash but even at a couple of stops below the main exposure this tends to drown the daylight and gives a very artificial effect: loosing what attracted us to the location in the first place