IMHO the best way to ensure that a bridesmaid can wear a dress again is to allow her to choose the design. I was a bridesmaid and the bride used this designer in Brooklyn:
http://www.kimeradesign.com/occdresses/occdresses.html
The bride chose the primary fabric for us to use (a red raw silk), and then let us decide on the shape of our dresses and what fabrics to use in the trim. I have worn that dress to many events in the last several years. I'm grateful to a bride with both good taste and good sense!
The photo album section of the site has lots of gorgeous pictures of wedding parties dressed this way (one or two shared fabrics, each dress is unique in shape and trim) -- they look unified, but not cookie-cutter. I think it's very sophisticated.
http://www.kimeradesign.com/album3.html