Thanks for your clear explanation. I will use a zigzag course for downwind. When loosing power I'll try to get back to a R.beam for more power.
Here is something that you said that confused me a bit: "Make sure your boom is high, otherwise you will feel scrunched up when you are in the straps with the sail racked back as you head downwind".
I thought that when going downwind the sail was racked to the nose of the board.
I also want to know about leg/foot position. Is the front foot in a straight position pointing leeward and the back foot bent for shock absortion. Or both legs bent and and back/body back of board for balance? Is the back leg pulling the strap or also pointing leeward?
Just curious. I've notice that few sailors never bend front foot when either going downwind or upwind. Is this a good classic technique?