I have been flying since the age of eight and i never tried a flat spin until about a year ago. The easiest way i found is to stall the plane add full rudder a burst of throttle then back the throttle off. Using ailerons to keep the plane flat. once you are satisfied reverse the rudder add another burst of throttle and snap the aileron stick to break the spin. This was on an uproar from tower hobbies. The blender works well too because of the momentum you are carrying. try it till you are mad then try some more.