Use a tape measure to set the desired seam allowance, by placing the needle into the tape measure at the desired seam allowance measurement and position of the pad at the end of the tape measure.
When you are sewing curved seams, place the corner of the pad at the end of the tape measure, giving you a point to follow.
This method of a seam guide works exceptionally well when working with children and when creating a seam allowance on the left side of the needle.
Sticky back notes are available in various sizes. Stock up on them at back-to-school sales.