I don’t like to wear my supplies in a backpack as it leads to sore shoulders and a sweaty back. Instead I use a rack and waterproof panniers by Ortlieb to carry my gear. Since I bring my entire office with me I use two panniers for balance and for organization: one for soft goods and the other for the office-y things.
If you’re not a morning person like me, try to get into a routine and put the same things in the same pockets every day. This will help you to not forget anything in the am mind fog.
Here is how my kit looks:
1) Chain lock plus cable for seat
Chain locks give you the most flexibility when it comes to what objects you can lock your bike to. If you live in New York you’ll also want a cable that you can thread through your saddle rails and back into the lock. It took a stolen seat for me to learn that lesson.
2) Patch Kit and misc tools
While I’m sure you’re all running puncture-resistant tires like Specialized Armadillos, flats can still happen. Toss the tools you’ll need in a ziplock bag and store it in one of the pannier pockets. If you use tamper-restant axles make sure to include the key so you can get the wheels off!
3) Plastic bag for bike seat
If you park you bike outside it’s nice to cover the seat in a plastic bag if you know it’s going to rain. Little things like this will help to extend the life of what is probably your most abused bike.
4) Cedar Chips!
While your commuter panniers are not a gym bag, there will be subtle sources of odor that can turn into a bad thing over time; your work clothes and shoes, dirty chain lock, outer layers shed in warmer weather, etc. Buy a box of these little cedar sashes and toss them in your shoes and all around your clothes and they will absorb moisture and odor before it sinks in.
5/6) Work Clothes
Obviously. Pro Tip: Pack a 2nd outfit! Not so long ago I was riding to work in a heavy downpour thinking I was invincible in my rain gear and hood. About half way in the rain was so hard that a stream of water formed on my face, dripped down my chin and neck and INTO my jacket and soaked my work shirt. A second outfit is also good for mornings where you sleepwalk out of the house. Remember those dreams about going to school naked? This will help to avoid that from becoming a reality.
7/8) Work stuff
9 Pedestrian Umbrella
While you may have all this high tech kit to get to and from work, sometimes you just need something normal to step out for a quick lunch.
10/11) Wallet and Phone
I keep these in my bags so they don’t get mashed/perspired on in my jersey/pants