I have a top waiting to be quilted that I am doing a scalloped border on. I figured out how many for each side with paper. I then used a dinner plate to get my curves. Took a bit of figuring to get the corners to work out perfectly.
I drew my scallops with my Frixion pen onto the borders to make sure everything would work out perfectly. Once it was drawn on, I straight stitched on my lines so I could iron off the Frixion lines. Since my border fabric was a pale yellow so I didn't have to worry about the Frixion pen leaving lines after ironing. If your border fabric is dark, use white chalk to mark it so you can erase any mistakes.
I will quilt the top first before cutting. Having the solid border allows you to FMQ up to 1/4 inch from the lines with still having the extra fabric to hold on to.