We always discuss the rules for our classroom and these can be summed up into five simple rules. I have created a poster with these rules, that I get printed up as a black and white engineering print at Staples for less than $3.00. I encourage my students to speak as much French as possible, all the time. To be clear, I teach a 50% French Immersion program and am currently teaching two classes every day. I teach French, Social Studies (in French), Visual Arts (in French), and Drama (in French) to one class, while the other class is receiving their English instruction and then we swap classes halfway through the day.
Although I expect students to use French as much as possible, I understand that students enter my class of varying abilities so I do try to provide a lot support so that my students know what to do if they don't understand something or if they need help saying something in French. We review strategies for speaking and listening in French. I have a poster set from PosterPals that has served as a great visual reference for my students. We go through the strategies with modelling and practice saying the different sayings that they can use so that students become familiar with what to do, where to look for help, what to say and how to say it.
In addition to the posters on the wall, I created my own "Feuille de référence French Class Reference Sheet" that contains the most frequently used questions and objects so students can easily access them. I place these on their desks/tables.
I do spend some time at the beginning of the year going over routines and how my classroom works. I introduce the Strategies to Maximize Communication in French. (See that blog post to learn more).