It's amazing how every quiller has her own method to fold a rose. I, too, have some tricks that I've never seen before, either on the Web or in a book. So, please welcome my — yet another — tutorial on making folded roses.
In order to create a rose like one in the picture, you will need a 3/8"-wide (~1 cm), 12"-long (~30 cm) strip of paper, a quilling tool and glue.
Step 1: Insert the end of the paper strip into the slit of your quilling tool.
Step 2: Roll the strip a little onto the quilling tool, making two or three turns. In the photographs I turn the tool counter-clockwise.
Step 3: Bend the strip out and down near the tip of the quilling tool, at an angle of about 110-120 degrees.
Step 4: Roll the the crease a little onto the tool.
Step 5: Make another crease close to the end of the previous one by bending the strip out and down again.
Step 6: Roll the new crease a bit onto the quilling tool.
Step 7: Repeat rolling and folding the strip, creating the rose flower.
Step 8: When you've used up the strip, take the rose off the quilling tool and glue the end of the strip down to the bottom side of the flower.
Step 9: Press the center of the rose down, the rolled end of the strip will peep out from its reverse side.
Step 10: Bend this end and glue it underneath the flower. This will keep it from unfolding.
Step 11: Hold the flower together until the glue dries up. You can see what its reverse side looks like.
Step 12: Now you may use your folded rose for a greeting card, quilled embellishment, etc.
If you want to make a folded rose with a stem, you'll need to fold the flower around a toothpick, a cocktail stick or a piece of wire. The process in this case will be a bit different. You won't have a loose rolled end that you can glue underneath the flower to hold the layers together, so roll the rose directly onto a toothpick instead of a quilling tool. First, glue the end of the paper strip to the toothpick before starting to fold the rose. Then follow steps 2 through 8, except that you'll need to apply some glue between the layers as you go.