I just finished Laura's Triple Irish Chain. The only request Laura had was for feathers and she wanted it special - it's a gift for her parents. I used my arc and made a plastic template. I marked each corner with the template with my marvy marker. I was able to do the feathers, pebbles as well as the frames all in one motion, just one start and one stop. The feather border was measured, marked, and then remeasured and marked, hmmm.
Ask a longarm quilter what tools they use most and you'll get a myriad of answers. Another great thing about this art form...so much variety.
For this quilt I am using One of Renae's arcs, a Sew Clear 6" template for the feather curls, a Marvy marker, seam ripper, tweezers, an audible book, and a handmade template. I'm sure there are more...:).