|It occurred to me that many of my students do not know the significance of sleeve notches. This may help newbies.
The armhole and corresponding sleeve have notches on both the back and front. The front always has ONE notch and the back always has TWO notches. This is helpful to understand. Also, I always snip at the top of the sleeve .
To make your life easier, if your front and backside of your fabric look similar be certain to mark the wrong side with chalk or painters tape or a easy to remove sticker. YOu will save yourself alot of grief.