I've had a little "back and forth" with fellow Blogger, the Urban-Agrarian. I had given her a suggestion about using an Espalier for some fruit trees she wanted to plant. Her space was pretty limited. She has since written a piece at her web-site about that process, including a photograph. If you're interested in reading and seeing something about Espalier, try going to that link, above.
I also have an article on Espalier from Ohio State University Extension.
There is a lot of information there so read, enjoy and learn!