Nothing puts a damper on a party like feeling self-conscious. Your 'maids mean a lot to you and you want them to feel ah-mazing, right? It may be tradition for all bridesmaids to wear the same style and color dress, but we all know that girls range in body types, which means means certain cuts and styles aren't going to be flattering on everyone.
Consider giving your girls the freedom to select their own dress! Not only are they able to wear something that reflect a bit more of their style, but they'll have that extra boost of confidence and comfort throughout the day (ie: no tugging on the dress). And bonus: they can see themselves wearing the dress again.
When taking the choose-your-own dress route, be sure to provide guidelines such as color family, length, and cuts. For example when planning my wedding, I allowed free reign of selecting dresses as long as they were black, to the knee, and were not strapless. It's up to you if you'd like everyone to be in the same exact shades or allow different colors in the same family can look pretty amazing (think various shades of blue or purples).
Not only will this choice made your bridesmaids love you even more, but it will also add a more personal flair to your photos!