Maybe I'm missing something, but it sounds to me like your method would result in the cones being to tight.
The QR skewer compresses the axle some, pushing the cones even closer together.
I get things really close, where I get slight binding when the skewer is clamped.
I then use my 2 cone wrenches to back off the cones slightly to just where I want things. Basically where you know there's a bit of clearance, but you can't feel it.