Every person's body has a different shape. And the same size dress made by two companies might fit a woman in totally different ways.

That's why alterations are so common, says Anna Chin, co-owner of Anna's Alterations in Charlotte, N.C. Even in a tough economy, people continue to fill her shop with jeans, bridesmaid gowns and anything else that needs work to get the right fit.

Chin offered advice on getting clothes altered:

Easiest fixes: The simplest and most common alterations are hemming, shortening sleeves and taking in garments at the waist. Making shoulder seams narrower also is usually a quick fix. You can always make pants shorter, but lengthening is tricky. Usually, you won't see a telltale line when letting out the hem on wool pants; lines are more pronounced on a fabric such as khaki. Hemming pants -- the most common alteration -- usually costs $7 to $9.

Challenging changes: A body type with a small waist and much larger hips poses some of the greatest challenges. Altering a bridesmaid dress, for example, for a woman with that body type is more involved. Prices vary depending on how the garment is constructed, but it can be $80 to $160.

Delicate fabrics such as chiffon and garments with fine netting or mesh are difficult to work with. Sweaters don't always look right when altered, Chin says. Some high-end knits are difficult to alter successfully. And detailed stitching or cording on some designer clothes doesn't hold up well when you try to make changes. A regular sewing machine can't duplicate the stitching.

After weight loss: Cutting a garment down one or two sizes usually works well. Sometimes it's possible to reduce the size further, depending on the construction of an item.

When going for a fitting of any item to be altered, it's best to wear the same shoes and undergarments that you plan to wear with the outfit.