I'm trying to create a leader using 8#  Seaguar Fluorocarbon and 20# braided fibers (Sufix 832)...

I follow the directions to the 'T' until step 4:  "Hold the loose ends and remove the pick.  Remove the loose knot by depressing the levers.  Tighten the knot by simultaneously pulling on each main strand; "

Question is: what is the "main strand"?  is that the short free strands? or the long strands going to the line and leader? 

How do I tell if  I did it correctly?  I'm not sure I'm doing it correctly so tthe knot is strong enough to be a leader.

TIA... Spokane Dude
 

the main strand is the standing line in better terminology.  

Any good knot, you tighten the standing lines last - that means you have a knot that self-tightens in use.  

 

The ends of the line that don't go anywhere, and that you will trim away at last are the tag ends.