This position is the toughest for me.  I am tall, 6'4" and have long legs, 36" inseam.   Cant seem to get where I can relax into the rifle like the prone position?  And not sure if I should be tight crossed legged, Indian style or with my legs stretch out in front of me and crossed.  

What am I looking for when I have a solid position?  What are the key indicators that i have the correct position?

I got some good info on the sitting position from this thread:
www.ar15.com/forums/topic.html?b=6&f=33&t=217802