I LOVE this method of extraction, especially for photos! It's super easy and fun! I hope my instructions will be easy to follow so you can be using this cool technique too!
First, start with a photo and make sure that in the layer palette, it is a layer, not a background!
Next, you are going to look on the left to your sideways tool bar and find the little icon that looks like a camera. This is the quick mask tool. When it is activated, it paints red on anything you want to create a mask for or "hide", so to speak. Also, make sure that your paintbrush is activated (and be sure your paintbrush is a hard one, not soft!). You'll notice that the colors are black and white (in the little boxes), even if you had color in them before. That's because the black becomes the "hiding" color or the red and the white is what takes it away. But I'll show you more of that soon! Just notice what I circled and make sure they are activated on yours, as well!
Then I zoom in to about 200% and I start to color, everything that I want to keep. In essence I'm hiding part of my picture or covering it up, so I can remove it from the background. For this picture, I want to cut out my son, in his bear costume! So, I started at the ear and using the paintbrush (with a little brush) I colored red. You can adjust the size to super small around the edges and then bigger to cover in the middle!
What happens if you make a mistake and color outside the lines? Easy! Just change the little box from black to white and use your brush to go over the parts of the red you don't want!
Once I had colored in my little bear with the red, I zoomed out to make sure I got everything! This is what it looks like now:
I unclick the camera button and it puts marching ants around the area I had colored. As you can see, I missed a small portion on the left side by his hand. It was easy to fix. I just reclicked on the camer button, went back and added the red and clicked again! That's it! Now, you'll notice that the marching ants go around my bear and around the whole outside of the picture. You want it to do this. For me, it was automatic because I was working so close to the edge. However, if the marching ants aren't all the way around the outside of the photo, then simply go up to select>>inverse.
And the last step is to simply hit delete! This takes away the unwanted background and leaves you with a crisp, clean extraction-ready to place it in some fabulous layout!!!
This method of extracting took me about 10 minutes-if that!