If the engine is mounted on the centerline of the wing, make it 0-0 with the wing. Make sure that you do not have ANY left thrust. Some guys will put in a tiny amount of right thrust just to be sure that there is no left thrust.
Launch the plane with the plane tilted with the right wing low.
Launch it fairly level and allow the plane to build up some speed in the first critical second.
Before you try to fly it....Look the plane over from the rear holding the plane at a full arm's length from your eyes.
Scan the entire trailing edge for "trueness"...no warps or twists. Look for perfect symmetry.

Thrust angles can be a little bit off before you will notice a huge difference in how it flies...but left thrust is NO good.