When I bought mine I fitted a 50mm f2.8 lens and took images handheld of the dealers book case on 51 point centre, far left, far right, top and bottom. Everything was fine and still is. Unscientific, but simple
As for Fine tuning, go out and have fun with the camera, if there's a problem which I doubt you will find it, but enjoy the experience. Don't look for problems that often don't exist.