This is not only a bag with improv patchwork but also a sort of improv travel bag too. I don’t have any clue about how to construct pants or any garment. The way I went about doing this was rather approximate as you will see. I am not going to give any sizes of fabric, jeans or whatever because it will depend on the size of the pants you use. Before you start, align the top of the waist jeans together and pin. Believe me it makes things better if you do this.