As is common with apparel, spaghetti strap dresses do not always come ready-made to fit everyone's individual body shape. Some alterations may be necessary to improve comfort and appearance, so that the look is not sloppy, or does not leave the wearer awkwardly tugging up loose straps all day. For a stunning fit, alter the straps, hem and sides of a spaghetti strap dress to perfectly suit your body.
Alter the Straps
Put the dress on and pinch the straps together at the top of the shoulders until they fit. Measure the length of the pinched part of the straps, then add 1/2 inch.
Turn the dress inside out and locate the stitching at the base of the straps on the back side of the dress. Mark the base positions with a fabric pencil.
Unravel the strap's base stitches with a seam ripper to detach the strap from the back of the dress.
Trim the straps to fit. Take off the measurement in Step 1 from each strap.
Pin the cut end of each strap 1/2 inch below the top of the dress back, matching them with the pencil markings.
Sew across each strap base. Blend the new stitching with the original stitching, if possible.
Alter the Width
Turn the dress inside out and put it on. Pin the side seams closer to the body, then adjust them so that the sides are even.
Mark along the pinned areas with a fabric pen, then remove the pins. Take the dress off and replace the pins along the marked areas, while the dress is flat on a work surface.
Sew along the pinned areas. Trim the seam allowances to 1/4 inch and turn the dress right side out.
Alter the Length
Determine the amount of length reduction needed and subtract 1 and 1/8 inch for a hem allowance. Be sure to consider what shoes you will be wearing with the dress, as this can change the desired length.
Trim the measurement in Step 1 off the bottom of the dress.
Fold the cut edge 1/2 inch to the inside and iron it flat. Fold it another 3/4 inch and iron it again. Sew along the topmost fold to finish the new hem.