There was a recent post regarding "can't get an edge sqaure" and someone mentioned the David Charlesworth video. Struggling with this myself, I purchased it and watched a few times...then applied the method for a recent project.
I must say David's approach works quite well for me. It gave me a different way to think about "flat" and a more measured way to go about it. Not to mention the cambered iron, which now resides in several of my planes.
If you read this David, thank you. It's made a big difference.
Phil