I've had problems developing a consistent toss since taking up the game last August. Only this week I decided to try a Roddick abreviated motion and instead of pointing my tossing arm straight up had more of an an angle like him and then realised after 30 or so attempts discovered how consistent my toss was
I found the key for me was a knee bend like Roddick with a similar trophy pose seem to have solved my toss. I concentrated on the trophy pose and didn't worry about the ball toss and everything went like clock work.
I've modified it slightly as I start my serving motion with a hybrid stance similar to Murray but then morphing into a Roddick like trophy pose. Combined with the trunk rotation plus more leg drive, I now generate more power with my serves.