We teachers have to take into consideration the proficiency level the students have at the moment of the class, having a class with students from different levels it´s actually an advantage, that´s why I first make them talk about themselves, so they can feel comfortable.
I keep the conversation throughout the whole class using the different lessons I am teaching. If someone picks the phone and starts sending messages and so, the other students can clap, so I realize about it, and that person has to dance or mimic a phrase.
Also, when they ask me the meaning of a word or sentence, I do not translate I prefer using visual aids, mimics, sounds, or if it is a Top Notch 1, 2 class, and so on, I give them a short definition before I use the resources I mentioned before.