Line Twist !!!

[BeadHead]

Ok here is my problem. I am realitvy new to Fly Fishing. So when my fly-line started to look like a Spring I figured it was Line Memory. I had read some on the subject and every manufacture Claims to have less than the other. I figured it must be a big deal. I tried several techniques to straightn it. I finally sent it back. What I learned was that my line didnt have memory but rather twist. A brief explination of how repetive roll caasting to one side or some side cast was sent to me. What part of my side or overarm cast should I focous on to prevent twisting. I am almost positve its in my cast but im not sure what I need to do to fix it. Any Ideas?