This is always tricky - but successfully done - shows you really know how to 'boss the fabric' around!
The location of what you see is a pointed band under the bust on this apron I was making for my daughter. Where the top of the point of the band meets the bust portion of the apron, is this 'Inside to Outside' Corner.
1. Stitch right along the stitching line (5/8" in this case) on the uppermost portion of this 'corner, pivoting exactly at the corner'. Clip right to the spot where you pivoted. See the photograph below. This reinforces this corner.
2. Opening up this clip, pin the stitching pivot on this piece EXACTLY to the intersection of the two seam lines on the other piece. Precision is important. See the photograph.
3. When stitching the two together, stitch right to the pivot intersection point, stop with the needle down RIGHT ON THE POINT. Then flip the excess up, out of the way as you see in the photograph, I have done. Note the fold going upwards, to the left of the presser foot.
4. Press from right side - checking your work This 'inside to outside corner' should look like mine.