To make a super simple headband is really easy.
To make it you will need 1/8 of a yard of knit fabric, thread, a needle (or sewing machine), a piece of paper, a ruler, a pencil, and a piece of string. With the piece of string, measure the area around your head. Measure that string against a ruler. Divide by 2. On the paper, draw a rectangle that is 6 inches by your measurement (half the area around your head.) This is your pattern. Draw a line parallel to the longer line and call it the grain. Draw a line next to (and parallel) to one of the shorter lines. Label this on the fold. Pin your pattern so that the fold line is on the fold and the grain line is on the grain.
Then cut it out. After that, un-pin it and pin it the long way. Sew it a 5/8 inch seam using either the back stitch or a straight stitch. Turn it right side out. Then fold 1/4 to 1/2 in of fabric towards the inside. Then put the end you did not fold into the end you folded. Last, sew a straight stitch or a back stitch to close it up. Now it’s ready to wear
Note you could put about 8 inches of elastic in it before you sew it up, sewing the ends of the elastic together, to make a scrunchie.