far from my idea teaching you of cast. I would like know as you thinking your cast.
When in our school we teach the cast, we pledge to teach the angular cast, run very fast, because if we dominate line and leader on high-speed, we can to do all things when we go to the fishing.
Once the students are ready, we teach them the specific casts, because now they dominate on the line and leader.
This result we have with line from 2 to 10 but the best from 2 to 5.
For to have a line and leader stretched allow at the fly land first in the water, in the forward cast, you have give the thrust when the rod is at 45°-50° forward. This is the first important element but there are many others.
Some frames from last my english DVD
Fly fishing Masters - Italian Fly Fishing School - Fly Fishing Masters