I'm a lefty, and can throw both ways. I haven't been playing very long and, at first, the backhand throw was the only way I could throw and get any type of considerable distance. Unfortunately, I could only get discs to curve to the right that way-- even if I used an understable disc.
I started throwing forehand with an Orc so that I could get the disc to curve to the left. I use a very light grip for these kinds of throws. The disc doesn't go very far, but it is good for those short dogleg-lefts, or for avoiding the huge drop-offs on 2 and 12 at Cliff Drive.
After a while I figured out that if I changed my grip a bit and held the disc a bit tighter, I could make a fairly long and straight throw with my forehand. This is great when I do it properly, but sometimes I think I throw it too hard, causing the disc to flip.
I need to work on consistency on both kinds of throws. My muscle memory sucks so usually I just have to take the good with the bad...