I took this photo and used the elliptical selection tool to focus the picture in on the center. I feathered the outer edge a lot.
I took this picture that and decided to fade out the background a little bit and bring the grass into focus more using the quick selection tool and the magic wand tool.
(You can't tell too much of a difference when the pictures are small but when they are larger you can.)
I took this picture and decided to bring the biggest flower into focus by feathering out the rest of the background using the elliptical selection tool.
I didn't do a lot to this picture. I used the magnetic lasso tool to outline the flower to sharpen it a little bit and then I blurred the background. I also used the quick selection tool in order to take the lower right-hand corner and draw in some color so that it looked like the rest of the background.