Remember to chain piece It is easy to become so absorbed in matching fabric to paper that you forget to chain piece. Chain piecing saves time and thread. Just slip the next seam to be sewn under the presser foot before removing the section before it. When the first section is clear of the presser foot, you can clip and remove it. Or, work in long chains, sewing several seams before clipping the thread and beginning a new line of chain piecing.
	Minimum seam allowance You've added the fabric, flipped it open and found the seam allowance short on one side or at a corner. In my opinion, 1/8" (3mm) is enough seam allowance if you're using a good woven cotton and your project will end up on a wall. If the project will be part of a heavier, larger quilt that will see use, 3/16" (5mm) would be my minimum seam allowance.
	For smooth points For the cleanest points, start at the wide end of a triangle and sew TOWARD the point whenever you can. This avoids sewing over the bump of the previous seam at the start of the point, which can lead to a wobbly seamline and a fat point.
See a Word About Pinning.
	Pinning at the points of triangles When pinning sections together that begin or end with the point of a triangle, place the pin immediately ALONGSIDE the point (vertical arrow), and not at the very tip of the point (horizontal arrow). The difference is tiny, but pinning the rest of the seam should be easier and sections line up better.
	How far is too far off the line? Seams should rest immediately next to the paper, but you can settle for an occasional seam that looks like the top example. The bottom example would force me to rip just that area and run a new line of stitches next to the paper where it belongs. In the end, the whole idea is to avoid undesirable "block growth."
	Pin with multiple seams UP When pinning two sections together, you have a choice to pin from either side. Sewing is usually a lot smoother if you place the section with the most seams "on top" and pin from that side. The side with the fewest seams would be the side that travels over the feed dogs.
	Avoiding thread show between section seams After pinning and sewing seam: (1) Check both sides of seam and free any tiny paper edges that may be caught in it. (2) Press the closed seam (see illustration). (I am a convert to this. It really does seem to "shrink" or embed the stitches more firmly into the fabric.) (3) Open the sections and press from the front, gently. You do not need to spread the seam with any force. Allow the seam allowance underneath to go to the side it wishes. If it does not go to either side easily, gently press the seam open on the wrong side.