The organizers of the "Single Girl" Quilt Along are taking turns sharing construction tips and techniques, so I thought I would join in the sharing. All of us working on these quilts are using Denyse Schmidt's very well-designed pattern. This is not a quilt that you can "fudge" on and get good results and this starts at the very beginning of the process. Since I'm working on my third "Single Girl" quilt, I am speaking from experience with the pattern as well as nearly 50 years of sewing. Accuracy is extremely importance from tracing templates, to cutting fabric pieces, to maintaining a quarter-inch seam in piecing.
Because you are piecing curves, the pieces do not line up perfectly as they go when you are piecing squares. I've shown the quarter-inch gauge next to the little corner of the fabric that hangs out when you start to piece.
Here's another view of the little tail of fabric.
Next, pin the other edge.
If you've been accurate, the arch and the background pieces should go together without much fuss.
This is a quarter-inch foot. If you are a quilter, it is worth every penny it may cost to purchase one for your machine. It eliminates guessing or the need to mark a quarter inch seam line. Get the right tools for the job.