The worst is over, actually. After trying various configurations of fabric/adhesive/paper to get the fabric through the printer, the foolproof solution was to buy full page labels and adhere the fabric to those. Worked flawlessly.
Another little discovery was to do a quick zip with a lint roller over my fabric surface before sending it through the printer.
NOW the big question is how to get the same color onto my fabric that I have in my digital image. I used a tightly woven, bright white cotton for today's prints...but they still came out kind of dusty toned. There is so much technical know-how involved in getting the printer to "see" the digital image on the computer properly...and I don't know any of it. So it is time to get busy and do some research...but any suggestions would be most helpful! And thanks!
I think you can see the difference in these two versions of my corner units...