I decided to try and make these for a small baby shower gift for a friend. They turned out pretty cute, so I'll share what I figured out.
Fold the washcloth in half with the fold on the right. Baby washcloths are very thin, so I found that if I folded that edge over again another inch then it made a fuller and prettier rose in the end.
Fold up the bottom corner and roll the washcloth up, tightly at first, along the folded edge so that the center sticks out a little farther than the edges.
Secure about half-way down with a rubber band.
Fold up the raw edge "tail" creating a flat base, then roll the edge back down to create the outermost petal.
Then I twisted some green pipe cleaners around the base of the roses, tied on some ribbon for "greenery" and wrapped the whole bunch up in tissue like a bouquet.