I used to be pretty successful in not getting my bike stolen by using one solid ringlock (axa) and a seperate cheap light cable lock. In my reasoning, there are generally two ways to steal a bike, either the thief opens the lock at the location of the bike and rides away with it, or he picks it up locked, puts it in a van or takes it home carrying it, and opens the lock with a power tool at home. With the solid ring lock, breaking the lock on the spot would require a powerful angle grinder with all it's noise. So it's wouldn't be the attractive choice for the thief that wants to bike away with his loot. For the thief who takes the bike locked and breaks the lock at home, it's unattractive because he still needs to carry a bolt cutter and cut the cable to detach the bike from some lamppost or something. So the thief would choose another bike to steal.

Now that I have bike that's a bit more desirable, I have replaced the light cable with a heavy chain that is locked by the ringlock, so taking the bike from the place I left it would require a grinder instead of a bolt cutter. This strategy is of course dependent on the fact that there always a lot of other bikes in the area which are easier to steal and mine is not that special. But in general I would advice to think like your local bicycle thief and lock the bike accordingly.