The best way to pack your Weekender Sneaker Back Pack is to fold your clothes flat and stack them, this allows the space around the clothes to pack your toiletry bag, socks & personal items. Ideally you can fit 2-3 days worth of clothes, you can squeeze more but understand the more the bag is stuffed, its less likely to fit under the seat in front of you on a plane but it will still fit in the overhead compartment (but even that is tight and you exposed your bag to scuffs). When packing, try to pack your laptop, cables and chargers 1st. Doing this will give you the best way to find out how many outfits you can fit in the bag comfortably.
Personally I like to pack my laptop charging cord in the zippered pocket on the front of the bag, along with my keys and a small note pad. The inside compartment I like to use for mobile phone & camera chargers and cables. The watch and accessories zippered pockets on the inside are great for storing jewelry and hand sanitizer (sometimes I only travel with one watch).
I'm not much of a hat guy, so most of the time I don't use the hat sling and I use the pouch to store keys or more cables and chargers.
In the sneaker compartment I just store two pairs of kicks, but I have seen some of you fitting 3 pairs of kicks (mostly Roshe Runs, Flyknits and Pure Boosts). If i'm going to an island or somewhere warm (Hawaii in a month #CantWait) I'll store two pairs of kicks, sandals & flip flops.
I travel everywhere with this bag, if you do to I know you enjoy it every time a TSA worker asks you to open your bag. I hope you enjoy your trips with the Weekender as much as I do.