Denied unemployment, how do I appeal? - what worked for you?

I got a denial letter last week saying I left my job voluntarily, but I was let go as a teaching assistant. It has been weighing on me all week. The letter lists a deadline and a hearing process, but it is hard to follow. If you have appealed before, what helped you prepare?

Stay calm and stick to facts. Mine lasted about thirty minutes and felt more like a conversation than a trial.