U-lock or Disc lock?

[darrsi]

There's a trick a friend used - he said it has worked for him - locking the bike with the front wheel against a post, or a wall, or some other obstacle and mounting the disc lock so that it is against the fork when the wheel is rotated backwards. That way it prevents the bike from moving/gaining momentum before the lock is removed.

It's a minor deterrent, but in the real world they'll just pick the bike up if they really want it.