Documenting my artwork for over 15 years, I've come to the conclusion that photographing your own work is virtually impossible.
Something always goes wrong when taking photos of two-dimensional art. If the exposure is perfect the focus is off, if the focus is perfect the angle camera isn't perfectly aligned with the canvas. Tripods, remote shutter releases, and professional photo lamps help, but not enough. I went through a phase when I would haul my paintings outside onto the sidewalks of Brooklyn in order to use daytime shade, while all the pedestrians would stare and wonder what idiotic thing I was doing and why I was taking up their sidewalk space. I've even been through the harrowing experience of trying to remove glare in Photoshop - it just doesn't work.
In the end, no matter how good the photos were, I would decide six months later that they were not truly accurate documentations of the original paintings, and I’d end up re-shooting everything.
However, I have recently reached art reproduction enlightenment. The solution is SCAN, don't photograph!
When I was faced with selling some dearly beloved paintings that I felt I had still not accurately documented, I finally broke down and tried scanning. Now, I’m upset it took me this long to try it. I had avoided scanning for the typical reasons: I thought it would be impossible to scan larger works, I figured the right scanner would be prohibitively expensive, I thought it would take advanced and painstaking Photoshop skill to stitch the scans together. Fortunately, none of this is true.
With a $75 Epson scanner and a handful of Photoshop tricks, my digital images are now true to the original works, and I have the high quality scanned images at 300dpi for printing reproductions to sell in my store.