I am working on a bag with a ruffle at the top. I currently have 200 stitches on my circular needles, but need to increase to 400 stitches and the pattern says that I will need to use multiple circular needles to accommodate so many stitches. Any ideas to help? I am unsure where to start with the second set of needles and how to work them so that I stay in the round. Any help would be appreciated.