Put the rudder and elevator on the r/h stick. Hold and throw the plane with the right arm (assuming you are right handed). Regardless, keep your thumb OFF of the stick during the throw. You will NOT be able to hold it centered no matter how hard you try. Hold the radio with your non-throwing hand but NOT the stick. Throw/launch the plane and immediately PREPARE to control IF needed with the right hand. Many glider types require more of a push or shove than a throw also. Throwing too hard is also bad. Concentrate on wings level and the correct pitch attitude during launch.