I mean, look at it!
Well, the answer is: you start thinking. You imagine.. you try different things, and then you grab your scissors and you start cutting.
And you find some matching trimming, some matching lining and a big button and you start sewing a little.
And then you sew some more and you iron (a lot). And in the end you get this:
One beautiful bag! Or maybe even this, if you happen to have a zipper around:
And then you become very happy and satisfied.
Do you want a bag too? You can buy a finished bag right here and the purse here (or take a look here if you're in Denmark).
If you would like to sew your own bag, I also offer sewing kits with everything included, ready to go cut up fabric and sewing instructions.