The first step is to select an appropriate photograph. It works best with a photograph where the main subject that will be popping out of the background has good, clean lines. A solid or fairly uncluttered background works well, especially the first time you try this technique. Hair can be a little tricky, but I chose to work with this photo for this tutorial.
There's no need to crop the photo at this point. You'll remove unwanted portions of the image during the course of the transformation.
Make a note of the dimensions of the selected photograph.