In a BCCE 2016 Plenary session, I mentioned that I have, display and live a class motto in order to give a framework to the scientific intent of my community of learners. My particular motto is a quote from Freeman Dyson:
"Science is an objective struggle between the precision of tools and the ambiguities of nature."
How could you turn this into a class activity to kick off the year? Teachers should research some possible motto choices to share with the students to motivate their own search. Students could help to find their own mottos. These could be displayed in the classroom during the initial weeks of class, revisited over time, and then voted upon after some weeks of scientific work in the course. The students would then have ownership of the selected motto and the activity can help build a sense of community. Although I alone selected my classroom motto, I do continually weave it into class discussions as we struggle with data examination in search of significant patterns to reveal an important regularity that increases our understanding of the chemical world.
Certainly this idea cannot be unique to me, but I have not actually met another teacher who lives a class motto as they lead students through a year of experiences in chemistry.