Bandeau tops are basic tops are shirts that consist of a single tube shape. These can cover just the bust area or a larger area of the torso. A bandeau top can be made from a bandanna or a scarf that is large enough so that it can wrap all the way around the largest part of your torso. Using a scarf to make this sort of top provides many different options for colors and patterns.
Measure the widest part of your torso that your bandeau top is going to cover. Find the center of your scarf and mark the length of your torso measurement along the top edge with a fabric marker so the center of the scarf's length is the center of your measurement's length.
Fold the edges of the fabric of the scarf on either side away from the side of the scarf you want visible when your top is finished. Pin the fabric this way and iron it.
Sew a basting stitch (a loose stitched) about 1/4 inch in from the edge of your fold on each side. This will keep the fabric from moving when you attach the zipper.
Pin the zipper to your scarf so the bottom of the separating zipper is at the bottom edge of your scarf. If your zipper is longer than your scarf, you can trim the zipper at the top edge and sew a small stitch on each edge of the top of the zipper to prevent the zipper pull from sliding off at the top. Fold the edge of the zipper under at the top and pin it in place behind the visible part of the zipper.
Sew the fabric to the zipper on both sides using a needle and thread or sewing machine.
Put your new top on inside out. Gather the fabric in the front so it shapes around your bust and use the safety pin to hold it in place. Add any darts necessary to shape the bandeau to your body using straight pins.
Sew the gathered area with a straight stitch and remove the safety pin. Sew your darts into place with a straight stitch and press them down with the iron.
Try on your top to be sure it fits. Cut off any extra fabric from the scarf ends and remove the basting stitch from the back.
Having a friend help you measure is often helpful to improve measuring accuracy. If you have a wide scarf and want a shorter bandeau, trim the excess fabric from the width and sew a hem.