I have been using my stones for about 3 years now and have never flattened them. They are Norton combination stones 220(which I don't use)/1000 and 4000/8000. The 4000 has a pretty good size dip in it.
Do I need to soak the stones before flattening? Is there a good simple technique to assure that the stone is level without using a level? After beveling off the edges, should I use a back and forth motion or circular? Should I bevel after flattening?
Is there anything else I need to know about the maintenance of my stones?
I do have a flattener that has the somewhat diagonal grooves in it. This all seems pretty straight forward, but I want to make sure.