I can't take credit for this tutorial. The link to the tutorial I uesd is her http://www.tutorialwiz.com/sphere/
I followed the tut. The one thing you will want to do is have an image that you have extracted the subject. Here I used a snapshot of my daughter at the pool. The more empty space the more the cage behind the subject will show.
I found the blending modes of the two cage layers to be up to ones preferences.
I added a new background layer in the shade of blue then added a blenging mode of gradient to the colors I wanted.
Have fun! Let me know what you can do with this tutorial or add to it.