How to launch a flying wing
There are numerous styles and approaches to launching a flying wing, there is no 'correct' way, each person has their own preference and style. The idea behind all the launch methods are to get air flowing over the wing so your aircraft can begin to create its own lift. Also you are wanting to guide your plane into the sky, there is no need to be trying to huck your plane skywards.
1: The "Sally Side Saddle"
This method involves holding your flying wing just off to the side of the nose by the leading edge. You throttle up to about 2/3 throttle with your other hand, (some people prefer to throw left handed so they throttle up with their mouth on the stick) and then you guide the plane into the sky by using a straight throw. Do not try to swing the throw around as you are likely to throw your plane in to the ground.
To ensure success of this launch method you would ideally have greater than a 1:1 power to weight ratio on your plane's power system.
This method can be used for wings of all sizes, from the Apex to the much larger TBRC 60. Here are a couple of videos showing the technique used on the TBRC 60.
2: Over The Head
Throwing over the head is a slightly more risky method as your head gets close to the propeller, but when done safely you shouldn't have a problem. This is usually done when you are launching the plane for someone else, as they can have their thumbs on the sticks right from the start of their flight. Before you throw your friend's aircraft be sure to check behind you that you're not going to be throwing it into a tree or other obstacle. To do this successfully you need to keep your arms as straight as possible, once the pilot as throttled up to about 2/3 throttle you will raise the wing up and throw it over your head. Be sure to let go when the plane is angled up at about 30 degrees from the horizontal. If you hold on too long you'll find that you'll throw the plane into the ground.
This method is great when helping out a newer pilot as your release is likely to be much more level to the ground rather than the other methods where you may impart a roll onto the plane as you throw it.
In this video below you can see how easy it is to launch even a very heavy TBRC60.
Here are some race starts which show a variety of launch styles all side by side