Finally! I have a strip finished in a size I like. This one is 18 stitches wide, all half-double crochet, on a J hook. It took an entire skein of Red Heart Super Saver yarn in the color Peruvian Print, and turned out 6 inches wide and 60 inches long. I'm going to edge the strips in Soft White, and I should have seven strips when I'm done, so it will make a nice-sized afghan. I'll crochet all the strips together, so there shouldn't be any sewing on this afghan.
I have to once again thank my friend Linda (aka Crocheting Fool) for the suggestion of crocheting this yarn into narrow strips. I really like this much better and I'm glad I decided to do a narrower strip.