Rag curling your hair is a fun way to get thick curls without using expensive styling products or excessive and damaging heat. The advantages of using rag curlers are that they curl your hair while you are sleeping, they don't cost anything, they won't damage your hair, and you can make and use them completely on your own. Plan ahead before using them, as you will need to let the curlers sit in your hair overnight.
Lay out a length of scrap fabric. Using your tape measure, cut fabric into rectangles measuring 3 inches by 8 inches. You can make a template using cardboard to help you, or you can use a quilting cutting mat, rotary cutter and straight edge. The rectangles do not need to be perfect---you can simply use a tape measure and scissors to get the desired rags. Use any fabric you happen to have, although fabrics with a sheen may be more difficult to work with because they are likely to slip and slide around.
Cut 20 to 30 rectangles out of your fabric. The number of rags you will need depends on the thickness of your hair and how tight of a curl you want in your hair. The thicker your hair, the more rags you will need, so cut your fabric accordingly. The rags do not all need to come from the same fabric; you can use whatever you have on hand. This is a great use for scraps of fabric you have laying around from old sewing projects.
Lay out all the rags neatly in a pile so that they are ready for use and easily accessible. Store them in a bag or shoebox.
Wash, comb and towel-dry your hair so that it is still damp but not dripping wet. Section off the top portion of your hair, letting the bottom half hang loose to be worked with first.
Gather a section of hair: The smaller the section of hair, the tighter and smaller the curl will be. Comb the hair down to the tips to detangle. Hold the rag perpendicular to your hair and place the tip of the hair in the middle of the rag. Fold the rag lengthwise over the tip, so that the tip of the hair is completely covered by the rag.
Holding the sides of the rag, roll the rag up toward your head as high as you want the curl to go. Fold in the sides of the rag and make a simple knot to secure the rag curler in place. Repeat this process for every section of hair until your entire head is secured in rag curlers.
Wear the rag curlers in your hair overnight to let them dry and the curl to set properly. Remove the rag curlers one at a time by undoing the knot and gently unrolling each curl. The curls will loosen as the day goes on, so do not be discouraged if they are initially tighter than you were anticipating.