Cologne-based tailor Sebastian Hoofs has published two more videos which perhaps find some interest here. They are in German, so being able to understand that language will help in following the procedures demonstrated, but most things will hopefully be clear even if that isn't the case. Perhaps one tip: he mentions "abgekettelt" a few times, which means overlocked (or serged), which I found difficult to see in the video because of the colours of fabric and thread.
The first video is about a method for making a slanted trouser side pocket. The variant shown has no adjacent facing, the pocket bag starts immediately at the opening, although he mentions the faced type as well.
My comment here would be that I always make the trouser pocket so that the bottom of the pocket bag runs downwards to the front and the front bottom point is always obtuse or rounded, so that no object (or dirt) can embed itself there, but that is just my preference.
The second video shows how to make a zipper fly in men's trousers. There are also some views of the band and instructions for making the fly-waistband transitions. It all looks quite neat, I think.
BTW, a hardened glass plate or table like he has is an excellent surface for flat basting, the needle point never catches.