"I have never been confident using tilts and swings. I understand what to do, but I'm never sure if it's right, and usually end up stopping down further than I should probably have to. Often donít bother even trying tilts when I should. In the end I've usually settled for more diffraction rather than risk a totally screwed up picture. I'd also like to point out the uncertainty regarding depth of field made its way into my 35mm work."
Get a good loupe which can be focussed on the GG, a good (meaning dark) darkcloth so you can actually see the GG, then focus on the GG.