Ok pros, what is the best way to do a flat spin & inverted flat spin ?

not to be short but it all depends on the plane

what type of plane you trying to do this with

Let's us know the hardware you are using, prop size/pitch/plane CG? aft/nose heavy,control throws, (dual rates for 3D) ect....
talk with you soon ...

Try some of these sites... Good luck!!!

http://bandito.50megs.com/rc/hangar.html

http://aerobatics.freeservers.com/

http://www.adam-flys.com/3d/

http://www.geocities.com/Pipeline/3589/index.htm

http://www.horizonhobby.com/articles/1022.asp

http://www.horizonhobby.com/articles/1033.asp

http://www.aerobatix.com/aerobatix/index.html