Crochet rag rug made from quilting scraps, mostly 2 1/2 inch wide pieces, but I was not fussy about it, some were closer to 1 1/2 inches. It's wonderfully soft. I would recommend using whatever colors you would like to stand out the most first, so that they make up the center of the rug. I think the colors are more concentrated in the center, so this will help you achieve a "theme color". Of course, random is always lovely as well. This rug is very soft and thick (takes about 2 days to dry after washing).
This is an excellent way to use up quilting scraps. It really made a dent in my stash. Total time spent was around 8 hours (or 4 movies). I would like to make another rug and sew together a few of my smaller scraps to use them as well.