Ok, this should answer, once-and-for-all, the question of how to get more distance:
1. Read everything on this site. Then read everything on the PDGA discussion board about distance. Next, watch all the videos on this site. View each one repeatedly, in slow motion if you can. Then study the frame grabs.
2. Find a mirror with as much open space around it as possible. The aerobics room at your gym or dojo is ideal. Practice what you've read and seen until it feels semi-smooth.
3. Collect a big stack of similar discs. Head to a field and throw them using the motion you practiced in front of the mirror. Do this for a couple hours.
4. Play golf using only your putter until you're comfortable throwing it hard off the tee. This could take a month or more. Then add your midrange discs, and play with only them until you've almost forgotten what a driver feels like in your hand. That should take a few months, at which point you can incorporate your drivers back into your game.
5. Observe better throwers than you every chance you get. Analyze their technique, and try to figure out where they get their distance. Also watch worse throwers than you, and see if you do anything they do.
6. Get some rest. Seriously.
Repeat the process for months, years, maybe the rest of your life. It's no quick fix, but you will get better.