I think I spent my twenties being bridesmaid to all my friends. I had a closet full of bridesmaid dresses worn only once. My sis finally took all them satin dresses one day and made a quilt out of them. It was actually quite beautiful.
It's interesting attending so many weddings and witnessing different customs and rituals. Some weddings bridesmaids don't do anything but show up and maybe throw a shower or two. Other weddings, the bridesmaid shells out almost as much as the bride. Some weddings bridesmaid receive a souvenir or thank you gift. Same with the groomsmen. They too receive groomsmen gift on occasion. Even if your bridesmaids and groomsmen pay for some of the expenses of being in our wedding, which, being the good friends that they are, probably don't even mind, it is always a good idea to have a small thank you gift for them. I think many brides or wedding planners overlook this little detail a lot of the time.