Several rules of thumb, learned from living in Amsterdam, bicycle theft capital of the world:

- always use two different kinds of locks, thieves tend to specialize in just the one;
- lock the bike to an immovable object;
- in such a way that the thief cannot easily apply force on the chain used to fix the bike to an immovable object;

- make your bike unattractive for reselling; paint it in a way that makes it stand out and unique; mount parts on it that are out of the ordinary;