I know this is a ladies forum but I think I can help. I tried for 1 1/2 years to learn a double haul, couldn't do it. I watched this video which told me to put down the rod and just practice the hand motions. No rod, no line. I practiced the motions for about a month until it was second nature (it takes 21 days to create a habit). When I picked up my 9WT and hit the beach I had it down in 20 minutes.
Double Haul Basics