Though it might seem like advice straight out of the 50's, poor posture can alter your
appearance. When our shoulders slump forward and our chin starts to jut out our breasts then sag lower down by our waists instead of resting at our chest where they belong. This gives the appearance of a poochy stomach while also causing lower back problems. By standing with correct posture you are instantly slimming your figure.
According to the American Chiropractic Association, these are the keys to the proper standing posture
Bear your weight primarily on the balls of your feet.
Keep your knees slightly bent.
Keep your feet about shoulder-width apart.
Let your arms hang naturally down the sides of the body.
Stand straight and tall with your shoulders pulled backward.
Tuck your stomach in.
Keep your head level-your earlobes should be in line with your shoulders. Do not push your head forward, backward, or to the side.
Shift your weight from your toes to your heels, or one foot to the other, if you have to stand for a long time. Besides helping your midsection look flatter, one of the most important factors of good posture in a fittings, is marking the length of the hem. Once a bride rolls their shoulders or drops their chin down it can change the length of the dress. This is why practicing to maintain good posture outside of just the fitting will help.
Shoes are extremely important for your fittings. Personally, I will not mark a hem without the exact pair of shoes that a bride will be wearing to walk down the isle. For one, your posture is affected by the height of the heel or lack their of. Also, bringing shoes that are similar, but not exact, does not help because even if the heel is only different by 1/4 of an inch the hem length will not be correct. You can make a dress shorter, but once it's cut, you can't make it longer again.