It's much easier to use clips instead of pins. Pins tend to distort the paper & fabric when pushed thru all those layers. I use the red clips (others use clips from the office supply store) and find my pieces lay flat as I'm sewing and the layers do not shift; and they are much easier to remove as I approach them to continue sewing. Basting is a great idea and sometimes I do that if the seam is long but usually I'm too impatient.