Every week or two I'll swap clothes at work (which consists of a few pair of socks and underwear, a pair of jeans and usually 3 shirts). Generally I'll drive to work at least once every couple of weeks and I'll take care of it there. If not, I wedge that stuff into a backpack.

Apart from that, the load consists of a wedge pack with a tube and tools, a mini pump and water bottle, and an Ortlieb medium handlebar bag with breakfast, lunch and EDC gear - phone, kindle, pocket knife, small flashlight, keychain (with glow stick and thumb drive), wallet.