This is a point that I overlooked for a long time.

When you sew following the grain of the fabric, you reduce the distortion. Most of us have at some point managed to stretch the edge of the fabric when it has been cut on the bias, across the grain. We know that stay stitching, running a line of stitches round a curve or a diagonal edge, stops the fabric from distorting when it is handled.

This idea is based on a similar principle. So:

• For seams, start at the widest point (like the bottom of a skirt) and sew towards the narrowest.
• For curved edges, start at the highest point, and sew to the lowest. So for necklines and arm holes, start at the shoulder, and for curves waists, start at the side.  Following the logic, when you get to the lowest point, stop, move to the next high point, and sew towards the low point again. So sewing in a sleeve takes two seams, one at the front, and one at the back, not one line of stitching all round.

For a long time, I used the quickest method. I’d sew down one side seam and up the other, or right round the neck. Sometimes it was absolutely fine. Sometimes the result was just a little odd. Now I know why.

Find out more about sewing directionally here.