Same Dress, Different Necklines
Why try it: If you want a cohesive look among your bridesmaids but don't want to pigeonhole anyone into a silhouette that isn't flattering to their figure or would make them uncomfortable.
How to make it happen: Pick a specific bridesmaid dress designer, and find a general dress fabric and hemline that you like. Then, check their roster to see what variations they have. If they have at least one option per every bridesmaid, it's a safe bet.
Let your bridesmaids go through all the options and pick their favourites. Be warned: they may all settle on the same one or two styles, depending, so if you want them all to be different, consider having them each give you their top two or three choices.