Here's the Tutorial:
1. Mark the pieces with any method you like at the corner. Depending on the fabric, I use disappearing ink or tailor-tacks. Here, I marked with disappearing ink. For the tutorial only, I marked the stitching line and the Right and Wrong sides (RS/WS). I used a 1/2" SA, but any SA will work.
2. Place pieces RS together, matching up notches, stitching line and corner "dot."
3. Stitch to the corner "dot." This needs to be EXACT!
4. With the needle down, lift the presser foot and rotate both pieces so the corner is facing you.
5. Clip into the corner all the way to the needle. It is OKAY to let the scissors touch the needle. This step is really important.
6. Rotate the pieces back to their original position so the piece on top (the inset piece) is back on the stitching line.
7. Now here is the only tricky part. With the presser foot still up and the needle in the fabric on the "dot," rotate the top inset piece toward you rotating it counter-clockwise. At the same time, rotate the bottom piece clockwise, so the raw edges will meet. The next two pictures illustrate this and the drawn on arrows show which way to rotate the pieces. Because we clipped the corner, we can do this easily!
8. As you can see, the pieces are still RS together and the raw edges are lined up on the correct line on the throat plate. You can't see it, but all the excess fabric is pushed aside under the inset (top) piece so that when stitching the 1/2" seam, nothing is caught in the stitching line. Then stitch to the end.
Here is the WS, right after it is stitched. By clipping and rotating the the pieces, it spreads that clip.
There is no need to clip the inset piece. The pieces automatically lie toward the larger piece. Press in that direction unless there is a reason to press the toward the inset piece. If you need to press that way, you will need to take a wedge out of the corner.
Here it is pressed from the front and the back.
Try It...You'll Like It!
Let me know what you think :)