How to Alter a Dress

Enlist the help of a friend. It's much easier to mark measurements if you have someone to help you. While you're wearing the dress, you can determine the appropriate alterations and your friend can measure, mark and pin up how much fabric needs to be taken in.

Remove old seams with a seam ripper. A seam ripper will allow you to cut the thread of the seam without damaging the fabric of the dress. Only rip out the seams that need to be removed.

Follow your markings to determine where to re-sew the seams. You'll need to take in the extra fabric, sew a new seam, finish the edges and then trim the excess fabric on either side of the new seam on the inside of the dress. Iron the seam flat to complete the process.

Alter the length of the dress by removing the old hem and ironing out the crease. Then, mark the new length all the way around the skirt and pin the ends up and under the dress so it's the desired length. Use a tape measure to ensure the new hem is even all the way around the dress. Sew the new hem, remove the pins and finish the edges.

Finish the edges of new seams on the inside of the dress in order to prevent raveling. Stitch a straight stitch along the length of the seam, about a quarter of an inch from the edge. Trim the edges with pinking shears, which cut a zig-zag pattern that reduces fraying. You can also use a serger machine to finish the edges.