Launching a glider is super easy, almost anyone can do it. So, there isn't much to improve distance except choose the glider you are launching wisely. The glider shown is called The Cootie. It uses the Rogallo Wing, a wing that works best with model airplanes of slower speeds. It uses the same principle to fly as the hang glider and is a engineering marvel. I know that doesn't have to do with the tutorial but it's a interesting tidbit.
Step 1: How It's Done
The steps are as follows:
1. When launching a glider always remember to keep the nose facing up.
2. Draw your arm back into L shape.
3. Thrust your arm forward.
You can watch the video attached below to see how its done. Make sure when you do it you have more success:)