A good lock is only part of secure bicycle parking. Check the stand first: it should be firmly fixed and shaped so that the bicycle and lock cannot simply be lifted over its top. Choose a visible, well-lit place where people regularly pass. It is worth locking the bike even for a short stop. If only the front wheel is secured, the rest of the bicycle can be detached and taken away.
Pass a lock through the frame and around an immovable stand. If you use two locks, secure the other wheel as well; the aim is to protect the frame and both easily removed wheels. Keep the locks close to the bicycle and stand, leaving little space to work around them, and try to keep them off the ground. Take lights, a computer or other quick-release accessories with you. These steps take only a little longer than locking one wheel, but address an obvious weak point.
Before a bicycle is ever stolen, note its frame number and save a clear photograph. That record can help establish ownership and identify the bike if it is recovered. The number is often stamped on the frame near the pedals, although its position varies. The everyday routine is straightforward: pick a secure stand, lock the frame and wheels, check that the locks hold firmly and take detachable items with you.