Start out with a pair of Mary Jane pumps.
Although you could just glue the pink ribbon to your strap, I am offering the following tutorial as a less permanent option. We are going to make a removable and reusable fabric cover for the strap, so measure the length and width.
Cut a piece of fabric equal to the length of the strap plus 1/2 an inch for sewing clearance. Make the width of the fabric twice the width of the strap plus 1/4 inch for sewing clearance. Cut a piece of ribbon the length of the strap.
Fold under one end of the fabric, pin in place, and sew. Do the same for the other end.
I used white thread so it would be easier for you to see what I am doing. Fold the fabric in half lengthwise. The right side (the side that you want shown on the outside when finished) of the fabric should be on the inside at this point.
Sew along the edge lengthwise. Make sure to back stitch at the beginning and end.
Cut away the excess fabric. Turn right side out. You can do this by using a pencil to push one end all the way through. Slip the fabric cover over the strap.
Buckle the strap. Slip the fabric cover over the buckle. Use hot glue to attach the ribbon to the fabric cover. Cut 2 pieces of ribbon one inch long. Taper one end of each piece. Attach the 2 pieces to the end of the ribbon located on the strap. Make the top part of the bow as shown below and use hot glue to attach it.
The Real Deal: It cost me $1.00 to make these accessories.