I'm no expert, but the first furs I ever sent to auction last year averaged more than the auction average for western coyotes, so I assume I am doing something better than most.
I remove as much of the cartilage from the ear as I can. I then let the ears hang back flat. I used boards like yours. I also cut little boards to stick inside and pin down the front legs and to pin down the split tail.
I wash the hides after fleshing, in the laundry tub. I use cold water and dish soap. I keep hand washing until I no longer wring out pink water. After the hides are turned, I brush/fluff the fur with a pet brush.