I use rulers by Kimmy Brunner. They are nice and thick, simple yet versatile. I have a strait ruler for SID, set of melon rulers for curved cross hatching, and a set of circles. All the rulers have slits so you can slide them around your hopping foot for additional sizes. I ordered them from her web site after taking her class quilting with templates on Craftsy. I believe her web site is
www.kimmyquilts.com