Although I dislike encasing my raw seams in bias tape unless it accentuates the bag, I make an exception for roly-nesters. A reader, Pfirsch, suggested Roly-Nesters which has a tutorial to create rather matronly boxy pouches. The technique is pretty simple. You make it like an unlined boxy pouch but you hide the raw seams in bias tape. The result is of course not as spectacular as ahem, my own Lined Zippered Boxy Pouch Tutorial. But it's a technique you can use when your outer fabric and lining are joined together.
For my little pouch, I was trying out free-motion quilting and I did it on my little sandwich of outer patched fabric, flannel interlining and lining. Since the sandwich is gelled together by the quilted lines and also the sandwich is rather thick, I felt the roly-nester way was the best option to create a boxiness.
This is the bottom. My free-motion skill is still shaky. It's really hard.
Here's the pouch inside out. I forgot to change the bobbin thread to match the zipper so it's all glaring.
Not too bad.