The way I like to do RC and SC questions was go directly to the solutions portion of the OG12 book with another thin, hardcover book. I would go through the questions one-by-one covering the answer. Then I would try and answer the question as quickly as possible (the main exercise to find the "root" of the problem), then I would check the solution to see if I was right. This definitely helped me improve my speed. This also helped me with accuracy, because I was spending a lot more time focusing on the process of getting the right answer. I went from 35V to 44V in one week.