I have a seat bag and Axiom Magellen rack/trunk bag. In the seat bag I keep tools and patch kit and attach my keys to the key lanyard inside the bag. In my trunk bag (I'm a 3 day a week commuter-- 15 miles one way) I keep sunblock, granola bars, lunch, and sometimes a book to read on my lunch break. Side pockets usually contain, spare cash (emergency use), wallet, and maps.
Nothing too unusual but, I just started commuting