I plan to set the tone early and provide multiple opportunities the first few weeks of class for everyone to have a voice. The TEP Facilitating Discussion website had great suggestions - I've used a number of them in class already! It can be extremely hard for teachers to do, but waiting in silence before calling on someone or rephrasing the question is very helpful for the students that are deep-thinkers, introverts, or just like to hear others speak first.
An activity I might employ is a fun camp-like game called 1-Minute Speeches in which a randomly selected student must try to talk for 60 seconds about a randomly selected word. The words can be anything, such as sandwich, cabinets, music, hammer, etc. This gets students to open up, think of something on the fly, and it ends up being pretty funny. I plan to do this at the beginning of the school year (at least a couple of times) and then randomly throughout the year as a warm-up activity or at the end of the day.