From my experience over the last few days (in which was the time my sweeping took a phenomenal jump) I've gathered that getting rest helps and eating meatloaf. Now, the meatloaf might seem odd, but I'm not going to argue what happened last night. I was sitting in my room practicing sweeping and my mom said "Hey asshole, there's food upstairs". So I went up and ate the meatloaf that remained and when I went back down to practice more it was a eureka moment. I even managed to do some full 6 string sweeping relatively clean and my 5 string sweeping had taken a noticable step up in quality and speed. Still tricky, but sure isn't my first day sweeping.