I launch my wings by holding the leading edge of a wing and giving it a side arm toss. Hard to explain in words, but I'll try. I'm right handed, but launch with my left so I have my fingers on the elevon stick (Mode 2).
To try to explain - extend your left arm straight out from your shoulder. turn your wrist and fore arm so the the back of your hand is facing forward. your thumb will be pointing toward the ground. Grasp the leading edge of the right wing. Reach arm back, give full throttle (I use my lips), bring arm forward in a smooth arc, starting below shoulder level and releasing at about shoulder level. Your arm will be swinging slightly upward. You don't have to launch level. The wing will level out on its own right away.
That is about clear as mud.