Sticky Norms

As we head into the fourth week of school here at Berkley, we all seem to be settling into our routines, the "first days of school" behavior is wearing off, and we are finally getting used to each other! With that in mind, this fourth week of school is often when my classroom can take an easy departure from its norms. So how do we (teachers and students) stick to those norms?  How do we keep them meaningful and intact?  What are your thoughts?