Beside taking a full shot, take one or more detail shots, and a shot with the frame, if possible. A detail can also be acquired by making a copy of your image, and then cropping to a section, and saving that detail image. Pick a spot it will easy to check for focus; I use my signature.

Cropped

You don't see the glare...until you take a photo. I was too close. 

Still to come—Resolution: What It Is and How to Increase Resolution, even with Your Phone 

Tips for Photographing Your Art Work:

DISCLAIMER: I AM NOT A PHOTOGRAPHER! It may still help to have a professional do certain important images, or pieces that are very dark, very light, or have shiny surfaces.

There are a few simple aspects you need to get right:  LIGHTING, FOCUS, ANGLE, and RESOLUTION 

Here are some tips that I have found are REALLY HELP when trying to get a good image of your art work:

FIRST, if using a camera, set the resolution to 300 dpi/ppi, or 3mp. A phone has one setting, but the information for higher resolution is saved (but hidden) within the file. That can be adjusted on a computer AFTER the image is taken. 

Glare on canvas

Detail shot, but out-of-focus

No glare–and yes, I did change the shape of the moon...

Shadows cast on painting because of frame.

Skewed view--cropping will remove too much image

1.  Always photo 2-D work BEFORE framing (because of reflections/shadows at the inside edges) and varnishing (because of the glare).
2. Be sure your camera/phone is not on a ‘filtered’ setting. That will really distort your image.
3. Brace your phone/camera so it does not shake. Rest on a table, chair, anything. If you have a remote button, use it. 
4. Be sure your object is ‘square’ or ‘straight on’ with the camera lens (parallel), not at an angle. Even a slight angle will mean that some corners get cropped, and shapes are distorted. 
5. HOWEVER, taking it at a slight angle may remove any glare, and there are photo-altering programs that can remove the shape distortion.
6. Be mindful of glare on the paint surface, it can create areas that are slightly washed out, especially some oil paint colors. This requires turning away from light. 
7. If you do turn art away from the light, be sure one side or corner is not darker.
8. Use natural light when possible; an overcast day is best. Beware of lightbulbs that cast a colored light. 
9. Take one photo with JUST the image, before you frame and then one with the frame (if framed).
10. OR, You can take the photo with the frame, and then copy and crop. BUT, if the frame is very light or dark, it may distort the light reading, and make the painting look darker or lighter than is correct. And it will can cast a shadow on the artwork.

3-D Work:

1. Take photos from the front, back, and sides. 
2. Be sure the background is either plain black, grey, or white. A black or very dark object may show up even darker with a white background, and vice versa.
3. You can touch your phone screen on the image of your art work to lighten or darken the exposure and show details better.

1. Photograph work BEFORE it is put under glass. It really does require a professional to take a decent photo under glass.
2. Since you may also be taking a photo framed (with glass) as well, be sure the mat is in excellent condition. Hair, lint, mold spots, or discolorations can keep work out of a show. 
3. If it is already under glass, you might need to get a professional photographer to help you. Setting up your tripod far away from the artwork and then zooming in might help, but no guarantees. Also, be sure the image is parallel to the camera lens, and lighting is off to the side or out of the way.  You may find yourself in the reflection.

LINKS to each section:

• photographing your work:

          •2-D under glass

          •2-D work

          •3-D work