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.