seams to me

Since I began sewing, I have learned a few different ways to finish seams.

When I was learning to sew in school, we were told to do a straight stitch on both seam allowances before sewing up the seam. 

When I started sewing clothes for my little girl, I zigzagged both seam allowances.

Then I began to zigzag the seam allowances together for a stronger seam.

I also learned how to finish a seam with bias tape, but I rarely use this method.  When I do use it, it is for armholes with tiny seam allowances.

I still use the zigzag method when sewing in sleeves and other curvy pieces, but more often I use french seams to finish seams cleanly without any raw edges showing.  

French seam.

I just learned, as in this week, how to do a flat felled seam.  So handy when making boys button up shirts because it keeps the shoulder seam clean and bulk free.  Plus you have some nice stitching detail.

 Flat felled seam.

Are there other ways to finish seams?