Find a friend and videotape them speaking NORMALLY at the camera. Play it back without sound (that'd be cheating 
) and test yourself.
I grew up in Rochester, NY but currently live in Northern England (til next week) and I found that it is very hard for me to speechread British people. I do much better with the people who sound like me. It makes sense cos they make sounds same as I do.
Your best bet though is to find a place to take good formal classes.
