I have done it three ways--hire someone, free-motion quilting, and tying. If you can't afford to hire someone, can you afford to take a class and learn how to fmq? And tying is definitely another way to get the job done. That is very inexpensive. It would be sad to finish your beautiful quilt tops and just let them sit. Try tying one and see if you like it. Some of my favorite quilts are tied. If you don't like the look of embroidery thread, you can use a small decorative stitch from your sewing machine. I did that on a rag quilt and it turned out really nicely. It was a kind of round buttonhole stitch--tiny, but it got the job done.