I recently prepared some pieces to submit to a local art gallery and decided to frame two of the small ones to set them apart from hot pads. I know there are different ways to frame fabric art, but this is what I did. I was happy with the results.
I bought an inexpensive frame with glass, removed the glass and all paper filling. I discard the glass because I don't care for the look of fabric pieces behind glass. Then I cut a piece of foam board the size of the frame. I like to use foam board instead of a mat board because I think it's easier to cut and work with, but it is a bit too thick to go back into the frame easily. I solved that problem by cutting and peeling back the layer of cardboard on one side, right where the little doo-hickies that hold the cardboard backing go. That makes the board compress so that it will fit into the frame.
Then I used temporary spray adhesive and pins on the corners to hold the piece in the correct place on the foam board. Then with a long heavy needle and strong thread, I made a tiny stitch through the board and the piece, trying to hit the ditch where the binding is attached. I repeated this stitch around the edges, tying the ends. The stitches and the cuts in the foam are hidden when the original backing of the frame is replaced.
Then the foam board goes back into the frame, the backing is replaced and the holders are twisted back in place, and here it is. Not too bad, relatively easy and inexpensive. It also has the advantage of not damaging the piece in any way, so you or a future owner can change your mind.
After posting, I realized I had an earlier, briefer post on this method, and had credited the idea to Deborah Boshert of Deborah's Journal. She should have credit for the idea, but I take credit for shaving down that foam board! Although it still takes muscle to force it into the frame, this helps a lot!