I originally thought I would pick up a cheap backpack from the thrift store and take it apart to trace pattern pieces. I found this one and I can't bear to take it apart because it's so lovely. Instead, I'm going to turn it inside out to trace larger pieces like the front and back main panels and the bottom, and then I'll just take measurements and add seam allowance for the other pieces.

By this, I mean the smallest, most forward-jutting pocket. I'm starting with the cargo pocket because that is where most if not all of the backpacks I've made have started. That is my plan -- to think about the backpacks I've made so far and try to construct a new design in the same manner.

Once I've got the cargo pocket done, I'll just keep going up and make the next biggest pocket. If that works out okay, I'll trace the main panels, the bottom, the zipper panels, and try to figure out how they made the straps.