After the front pocket, the back pocket gave me some trouble too. I made the first one and had to do the topstitching around the welt (as seen in RTW ) in two passes. Not easy to work and I thought of doing it another way.
In the past I've found many tutorials on (welt) pockets, but not this particular one. I decided to make the opening first and adding the welt later. Inspired by the method that Ann shows (which she described in an article in Threads too, and I've found the same technique described by Claire Shaeffer) .
As I was making a sample, I made pictures so that I could share it with you.
Notice my new sewing foot in the fourth picture, it is open in the front so that you can see exactly what you do. I already know it's worth every euro I paid for it.