I bought some 12/4 hard maple to make a Moxon vise. I cut it to rough lengths a couple weeks ago and today I started to do the rough milling. Then the plan is to let it sit for a week or so.
I immediately ran into some warpage on both pieces for the vice. The first one I struggled with for a while then I came into the house to take break. I signed on to FWW and immediately found a video showing how to joint a warped board. Using that technique, I returned to the shop, and it only took about 3 passes to joint the warp out of the face. The second piece went much faster and it had a larger amount of warpage.
Basically one just places their weight in the middle of the board and keep it there as you push the board through the jointer.