Compositing with Photoshop is one part technique and two parts imagination. In the example below, I’ve created a dark and mysterious scene with a young girl paused in an eerily calm storm. Here’s how I made it:

View the finished composition

As you can see, the final result is a compilation of several layers blended together with thematic color correcting. Adjusting the mood of the scene by tweaking the color balance through the use of adjustment layers brings the image together as a cohesive story. Simply sandwiching layers on one another won’t produce the same effect and fail at convincing your audience. It all starts with an idea. In this case: a theme of ominous beauty.

Your first order of business would be to scour the stock archives for imagery you have in mind, while in the process, almost certainly developing on your idea with what becomes available. For this tutorial, follow along with the examples I’ve provided to get an idea of how it all comes together…

Read more : http://luxa.org/tutorial_compositing_with_adjustment_layers.php