Derrel already addressed the lighting, so I won't reiterate.
The composited background isn't really working though with all that halo stuff around her that doesn't allow the texture that's supposed to be behind her show between the hair and around the clothing.
This was shot with a very 'busy' background which needed to be photoshopped out. Normally, I would lasso around the subject and cut/paste onto a background. With the hair on this portrait, I didn't feel comfortable with that technique. Anyway, you can see the 10pixel perimeter around the subject and it does take away from the photo. I am looking into photoshop techniques to remedy that but seems complicated. The technique I am trying to experiment with now is taking the file, removing color from it so it is monochrome (differnt shades of gray), to separete subject (hair and all) from background. Am I on the right track or is there an easier, less complicated way?
For most of my masking needs, I use a PS plugin from Topaz:
Topaz ReMask - Masking Made Easy It works really well 99% of the time, including on hair and fine details. If you get it, be sure to watch their tutorial videos on how to use it on their site, as they're invaluable to get the most from the product.
For the other 1%, where subject removal from backgrounds are REALLY difficult to deal with, I use it in conjunction with what I've learned from Deke McClelland in his masking techniques series on Lynda.com here:
Photoshop Masking & Compositing: Fundamentals
Photoshop Masking & Compositing: Advanced Blending
Photoshop Masking & Compositing: Hair
In that series, you'll learn all the methods known, but the most powerful is to use the appropriate channel(s) to get the most contrast between what you're trying to mask and the background you're lifting it from, and that can vary from area to area in an image, depending on lighting, color, how busy the background is, etc.
The best way to deal with it though, is to pre-plan your work enough to know when you'll be making a composite beforehand, then use an appropriate background with your model to make it a lot easier on yourself later. For light colored hair, use a black background. For dark colored hair, use a white background. In both cases, keep the model as far from the background as possible to avoid light bleed and contamination issues. Clothing is generally pretty easy, either way, as long as it's not the exact color of the background, and that can usually be addressed with proper lighting during the shoot if looks like it could be a problem.
There's always the green-screen path as well, but I wasn't terribly happy with the results when I tried to work with it, while others say that's what works best for them. I probably just needed more practice with it.