In an upright flat spin follow hubers directions and once it is flat add some down stick. This tightens it up and for some reason can actually make it climb??

The easiest way to get a plane to do an INVERTED flat spin is to "blender" the aircraft into the flat spin. Start up WAY high, cut the power push the nose straight down, hold full left aileron, after 2 or 3 rotations, suddenly add full left rudder and full down elevator, hold all of this for a few sec. and watch to see what it does. If you do this right it should be a series of rolls into a blur into a inverted flat spin (that all but stops). This manuver is easier to do with airplanes like the edge 540, extra 330, cap 232 and so on.