My ruffler attachment in action - impressive, isn't it?
But it isn't something you just attach and instantly start sewing, it takes a bit of practise and patience to start making good gathers. I found an e-book on you can make this which is so useful! You have to register to download it, but registration is free, so if you have a ruffler and need a bit of help, or you are just interested in finding out if it's worth getting one I'd recommend you download the book and have a look. It's very comprehensive (30 pages!), with lots of pictures to illustrate and shows all these things you can do with a ruffler I never knew about (and weren't in the instructions that came when I bought it).