I bought that very same pattern earlier this year at the Road to California quilt show. I bought the matching ruler too. I haven't started the quilt yet - and now I'm a little afraid - but I fell in love with the quilt, which was being used as a cover for a display table.
All the Sewkindofwonderful patterns are designed to use their rulers, so I second bear's opinion of getting the ruler if you don't already have it. You might also check out some of the videos on using these rulers -
https://www.google.com/webhp?sourcei...derful&tbm=vid.