I can't do the above grip.... My hands are too small....
I use a similar grip, the end of my index finger tucks but only slightly. I put pressure on my 2nd joint through the flight plate with my thumb.
Really though, the warm-up, run-up and follow through are more important than anything in this throw.
I push em to like 300ft, gotta stretch the arm before hand. Then you have to find a run up that works for you, I aim with my left shoulder on my last step (rhoh). Then the follow through should be the same as any other throw, use a fluid motion if you throw it vertically follow through is down, if you throwover your shoulder on the right, you follow through down to the left. Without the follow through, you WILL hurt yourself after 1-5 throws.