One thing I'm learning with each gallery show I participate in is that it's not just the art but the presentation. Before I'd be content to display the art in a simple glass frame. Now I buy actual frames, because beside making it look better on a wall, it also means that if somebody buys the artwork they won't have to also buy a frame for it. I noticed that in the last show I was in ( still going on here ) that even with a frame but no mats within the frame, my pictures stood out, and not necessarily in a good way. I just liked to have the images as large as possible so I would print on an entire 8 1/2" x 11" sheet ( as that's the largest I can do on my printer ). So now I'm using frames AND mats, especially for the upcoming RAW show, for which tickets are still available, until Feb. 21st.
I do try to make the framing as unique as I can, when possible. I think it's helped sell a few pieces in the past.