Rules inform behaviour; behaviour becomes habit; habit gets rationalised; rationalisations become attitude; attitudes become character. Usually we look to modify behaviour from the top down, changing our attitudes first, and hoping that the effect will flow down. The thing is that an attitude is a hard thing to change, especially when your actions aren't already backing it up.
Mokalus of Borg
PS - My own attitudes change more easily in response to my actions.
PPS - You really should try it both ways and see what works.