have a look at my Cougar review, thats how i did it....
start in a wind, hover, then slowly slowly get the nose higher and higher and work the rudder more until your hanging.
problem is how a SPA3D and Cougar hang, it totaly different to how a low wing 3D or scale jobby hangs.
heres a susgestion, build a SPA3D with the extra's outline, inculding wing to tail relation and hopefully it'll make the rudder and feel more similar to your bigun than a funfly.
most of all burn gas and DON'T TOUCH THE GROUND!