If the bike is locked outside you need to make different choices than if its kept safe inside. Also if you have a job where your daily presence is not considered a necessity for someone's life, that can change your approach too.

I go 12 miles each way. I carry a road morph pump, spare tube, patch kit, levers, mini multi tool and a cell phone with taxi cab number stored in it. I also have a road ID that has my bosses number as an emergency contact.

My bike has full fenders, disc brakes and the best lighting system you can get.