I discovered Bonnie Hunter of Quiltville several years ago. Her "scrap users" system and "leaders and enders" helped me to tame a 15 year collection of scraps. My DH threatened me with "use it or lose it", so I began taming my scraps.
Every time I pressed seams etc., I also grabbed a handful of "scraps" and pressed them as well. They were then placed on my cutting table. The next time I was cutting, I also cut up the scraps into usable strips and squares. I don't save all the sizes, as I am limited in my storage space, but I do save strips, (minimum length 12"), in 1 1/2", 2", and 2 1/2" sizes, as well as 2" squares.
I have 2 bins beside my sewing machine, and every time I finish a seam, I pick up 2 squares and stitch them together, then trim the threads between the squares and my sewing. The square stays in the machine until the next seam. This way, almost all my thread is used to sew (I'm a bit frugal at times!)
When the pile of "2 patches gets too large, I stitch them into 4 patches. The 16 patch block in the picture was made this way, and made its way into a quilt as an alternate block.