First of all, let me say it's pretty good for a beginner

.
For improvements, I'd say avoid using the outer glow and standard Windows fonts, go over to
DaFont and choose a nice one, with fragrances you need to use thin fonts that say "class". I'd choose one with a couple of swirls, and that is quite thin.
It also seems you've got two focus points, the "5th" and "element" need to ideally be together, think of the people you're pitching this to as retards. Next, your tagline is a little long, and the staggering font isn't really suited for what you're trying to portray. Use a thin, easy reading font, maybe have it all capitals, or even italic. Keep fooling around and don't forget to save a copy before making drastic changes, I've made HUGE mistakes and wanted to go back but couldn't.
The strong use of black and white and then the colour is a little amateurish, but don't worry I've seen
a lot worse. I'd suggest using a gradient map or a filter to get a nice "cool" feel to it, again keep fooling around with things and see where you go. Some people would suggest using a black and white gradient map, but I think your blacks are dark enough already.
I really like the font sizes you used, they're spot on because you can see what's the title and what's the tagline (apart from what I mentioned earlier about the gap between "5th" and "element"). You also didn't cover the model which is good, but remember it's OK to cover certain parts (leg and torso as a rule of thumb, depending on the product your pitching). Make sure that the face and neck are definitely showing when pitching fragrances or any beauty products, it's important.
I hope I've given you enough to go on, I've been using Photoshop for about 4 years now, studying at college and now briefly at University. Some people may disagree with my feedback, and I'm expecting people to, but you'll always get
someone disagreeing with your methods, especially with such in-depth software like Photoshop (for image editing anyway).
Post up your results if you choose to edit it, I think you've got great potential and you should get a good grade for your work.