The corner seam is useful when color blocking is desired, especially when working with geometrics. Don’t confuse this with square edges, such as a neckline or armhole. This is an actual seam within the garment.
You will encounter curved seams a lot, such as armholes. You will be sewing opposite curves together. One side will be concave and the other will be convex. When sewn together properly, the two will create the perfect curved seam.
The French Seam is predominately used on finer and lightweight fabrics when overlock/serger isn’t appropriate. It can also be used on medium weight fabrics when there is a long seam and overlocked/serged seams are not desired.
This sample exercise is both utility and decorative. After sewing the seam and overlocking/serge the seam closed, press the seam to one side. Flip the garment to the face side and stitch on top of the fabric through the seam allowance.
The bust open seam is used to lower bulk on seams. Using the overlock (serger) is a quicker way of achieving the finish of both seam allowances. Once you sew the 1/2″ & 3/4″ seam, you will press it open flat (Bust Open), then overlock/serge each seam allowance separately.