It helps, for me at least, to simply realize that it is my mind, my imagination, my own personal "Matrix." My thoughts are law. Try to become comfortable with that idea, make it inherent knowledge that you are God in your lucid dreams.

Whether or not you really are "God" in your dreams doesn't really matter. Simply the automatic belief of having omnipotence will make your actions (which you are used to thinking of as "breaking the rules of reality) much more natural to you, and that's the important part. Passively letting your will be done, as it were.

Good luck. =]