How long should a sash be?
Depending on the size of the dress, the sash should be between 60 and 180 inches (152.4-457.2 cm) long.
How do you make a fabric tie belt for a dress?
Place two waist tie fabric pieces together with right sides together. Pin in place along all sides except the shorter straight end. Repeat with the other two tie pieces. Sew around the three raw edges, pivoting at the corners, and leaving the short straight end open.