Get a strong chain or a beefy cable. Fuhgeddaboutit locks are very reliable (they also make a fine weapon in a pinch). Make sure to wrap the chain/cable so that there is as little free space to get a set of chompers around it as possible. Make sure to include at least front wheel, if not both wheels, in the wrap. Lock should ideally wrap around the post, front tire, and frame. Try to make sure yours is either better secured or less valuable, or both, than your neighbor's. Install a discreet gps locator. Don't leave valuables attached to the frame while it is not directly in your custody.

Be careful not to include another's lock/frame/chain in your wrap. Not only is it extremely inconsiderate and inconvenient, it is a common tactic for thieves to lock someone's bike and come back to it later on the expectation that someone who doesn't know better will assume good faith and come back tomorrow, by which point the thief has had all night to work.