When I do towels I use wash away stabilizers. The terry cloth of the towers is study enough and you don't need to add too much more stability to it. In the case of towels, what the stabilizer do is to help you fold down the little threads so that after you are done stitching, they don't come back and cover the embroidery. I also use a small plastic sheet on the top for th same reason. The place where you get your stabilizer should carry it. when I am done I can see the embroidery very well.
Maria