The only way I locked my bike up, is when I am looking at it. Period. Other than that, it comes with me. I had one bike stolen about 25 years ago. It was recovered the next day. I learned from that. I wouldn't leave a bike locked up unless I am looking at it, or I have my very, very rusty beater bike. I carry a small inexpensive cable lock with me. I will locked up my bike when I go to eat in a cafe. I make sure I am not more than 20 feet from the bike, and I am eyeballing it too. Call me parinoid, but I ain't writing in that my bike has been stolen.

I always carry a spare tube, and a mini pump too.