This is a basic patchwork bag tutorial using scrap fabrics. This tutorial is posted in my BLOG years ago.
FAQ :
1. What interfacing do you use?
Interfacing depends on how you want on the look that you want. It totally depends on you. I love a soft pouches. I normally use fusible interfacing and flannel or fleece batting (that's a substitute for fusible fleece). For a stiffer pouch, I use canvas interfacing.
2. Batting
As I mentioned, I usually use flannel for quilted pouches or bags. Flannel gives a good structure and enough softness. I use fleece or cotton batting for gadget cases.
3. How to reduce the bulk?
Always cut your batting 1/2" smaller than the main and lining fabric. If you use thicker interfacing, cut the interfacing 1/2" less than the main and lining fabric. That will save you lots of headaches struggling with the machine.
4. Ironing is also very important. Iron your interfacing well. I normally set in Cotton and always use the DRY setting. Iron your fabric first then attach the interfacing. If you use anything other than cottons, like silk or cotton mix, do not iron on the fabric. Iron nicely on the interfacing, reduce the heat to (silk/rayon) then iron gently.
I hope these pointers will help you start your first bag making journey :)