In my opinion, I think the best casual backpacks out there are ones that are simple and refined. The main point of a backpack is to be practical and help you carry things around and I believe we should remain true to that idea. When I look for backpacks, I look for ones with a simple color scheme with my favorite being dark blues, tans, or black. From a style and brand standpoint my favorite current backpack brand is Herschel Supply Co. Below are a couple backpacks from them that I think are really great options to get to boost your backpack game. Check it out!