You can use a 9 or 10 degree ruler. Mine is the 10. I bought it a year ago during a special at Philips Fiber Art. I paid $19.95 for the ruler and received the pattern and shipping free. It is easy as long as you follow the directions, but I guess you could say that about almost any pattern. I tend not to use many patterns. The only change I make is adding the binding. The pattern says to put right sides together , stitch and turn. I think I prefer binding, though I wish I had bound the light side of this in the light fabric, but the seams would be tricky. The turquoise/orange one I posted several weeks ago had dark edges and a light center. This one is just dark to light. I'm not sure which I prefer.