Things to Avoid
Ceiling, spot, and track lighting can harm artwork because of the potential change in temperature. Keep lights at least 12" away from your picture to avoid your piece from being damaged due to heat.
Oils and moisture from your skin can stay as a permanent addition to your artwork if you're not careful. Handle with care and do your best not to touch the image area of a photograph or original print. This is the same with matting. Fingerprints are nearly impossible to get off and always leave a trace.
Humid conditions are very destructive if moisture comes into contact with prints or photographs. The surface can become warped and experience discoloration. Keep your artwork away from bathrooms if you can and avoid this problem altogether. Most other areas should be fine in a home or office setting.
This may seem obvious, but it's surprising how many people do not consider the dangers a certain environment may present when choosing to display a picture. Do not hang a valuable piece next to the stove. Oil can splatter and stain your needlework. Similarly, do not hang a picture in an area of high traffic, especially with children. Pictures can easily get knocked off the wall, and no one likes to pick glass out of the carpet.
Artwork can be very affected by light; specifically by harmful ultra-violet rays. Enough exposure can lead to damaging the image's texture and color, so light should be an immediate concern when hanging a picture. Do not hang across or on the same wall as a window. If you can't avoid it, cover your piece with a sheet when you can in the daytime, and be sure to draw the curtains if you go on holiday.