1) Turn around and backcast - good for putting out a long line where accuracy isn't a big factor.
2) Make the cast off the "opposite shoulder" - useful for shorter casts requiring a bit more accuracy.
3) Cast with the left arm. Just started seriously practicing left handed this year. Short distances are pretty fair with good accuracy. Next step is getting the haul going and I'll have a "full quiver".
In cases 2 and 3, I reverse the angle of my body by bringing my left foot back (as opposed to my right for RH casts). "Opening up" frees up the left side rotation and makes these casts a whole lot easier