I've heard differing methodologies on keeping scrap, particularly if one wants it ready to go for the next project. I keep a plastic tub of 2" wide strips. Not sorted, just tossed in there. Also in that box is a smaller box of 2" squares; all the "This is too short to do anything with" bits get trimmed up and tossed in there. If I didn't keep it all in one place, I'd never find any of it when I needed it. This is the famous bin mentioned previously in basting a project on the kitchen floor.
Retrospectively, I should have gone with 2 1/2" strips, since that's the width of a jelly roll. I'll have to work through my bin and start keeping new strip company. The public library has been an excellent resource for books.
One book offered a bag project. And I love bags. I did modify it slightly, because it didn't sound big enough. Also, the pattern wanted you to line the bag. Again, I adapted it. It takes a bit of extra work, but then you don't need a liner if you don't want one. Otherwise just make a liner and stitch all the bits together. Or make faux French seams.
If your jeans were made properly, the seat of your pants and likely at least one in the leg is done with a French [aka flat felled] seam, and not simply stitched together with a serger [all the loopy stitches] A French seam is reinforced [ah hah, yes, we'd want that in the seat of our pants, wouldn't we?] making the seam able to withstand a lot of stress. Don't ask me why it's French. It may be one of those things like French braids, fries and toast. Nothing to do with the actual country. A faux French seam has the courtesy of a French word in in, but rather than grade [trim down[ one of the seam allowances, tuck the other, longer one over it and top stitch down, you press both seams flat in one direction and top stitch them down, leaving the raw edges hanging out there. It does still stabilize the seam. There's just a lot less work involved.
The deal with this project is 3 squares of equal size that are sewn together in such a way that the two sides of the bag form triangles when viewed from the side. First, the two sides are sewn together, making a long rectangle. Then, one at a time, each side is folded in towards the middle, the sides are aligned, and one of the aligned sides is stitched together, starting from a finished corner making an L shaped seam. The process is repeated on the other side with only remaining free edge of the middle square and the opposite side being folded in towards the square and the raw edges aligned. The end result is a bag something like the picture on the right. I say something because I didn't line it. My friends are calling it the quilt bag.
I'm not certain if this bag is supposed to mimic a furoshiki tied up as a suika tsutsumi [watermellon carry wrap], or a katakake fukuro [shoulder carry wrap] with the exception that it is stitched into a bag shape rather than left as a square of cloth; the author didn't give any hints as to the bag's origins besides "Japanese" - I find that annoying, but I digress. My upsize resulted in what I think I'll refer to as 'gigantaur", and it was only two inches bigger than directed.