Shopping for bridesmaids dresses is not easy. You have to find a dress that will fit and flatter each girl and that's not even the headache of trying to schedule shopping appointments when everyone is available.
When you find a bridesmaid dress that you like schedule an appointment for as many of your bridesmaids to go with you to try it on. For those who can't make it, see if it's available in their area and have them make an appointment and email you a photo of themselves in the dress so you can see what it looks like.
Once you've picked a dress make sure each bridesmaid gets her measurements done correctly, the sales consultant can give them directions, and confirm that everyone has ordered their dress in a timely manner.
You should always check the store's return policy but I'm gonna bet that once ordered you can't cancel the order for a full refund so only place the order, or have the bridesmaids place their orders, after they've all tried on the dress, you've decided that it's the right color and style for your wedding and you are satisfied that everyone looks great.
Don't worry too much about picking a bridesmaid dress they can wear again because no matter what you choose they probably won't wear it again. Sorry, that's the truth.