Sweetbriar Classic Vintage Messenger Bag - Original Heavyweight Cotton Canvas Shoulder Bag with Upgraded Features

You sound like a candidate for the Chrome Kadet messenger. Or just go old school and get the Sweetbriar Canvas messenger. The canvas will take to patches, buttons, or spikes nicely. This is what my son carries almost daily. He dresses in an emo/alt style. Extra point because it’s not expensive at all. I’m actually in the process of waxing a new one of these so he has some basic waterproofing in the winter.