That depends on what your requirements are.
Even though you are being “nice” by letting your bridesmaids choose their own bridesmaid dresses, you should still set some parameters as to color, length and formality. You want everyone to complement each other, especially in formal portraits.
If you want a relatively easy color to shop for -- black, navy, white -- then your ‘maids shouldn’t have trouble shopping at department stores or mall shops. But, if you’re requesting a specific shade -- coral, lavender, sunny yellow -- then they may have the best luck at a bridesmaid dress retailer.
A bridesmaid dress retailer will offer a variety of styles, by several designers, in a rainbow of colors. Each girl will easily find a flattering silhouette in the color of your choice.
Some national bridesmaid retailers include, David’s Bridal, Bella Bridesmaid and the online retailer WeddingtonWay.com.