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 an electrician's helper. 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?

I printed my emails in order and wrote a one-page timeline. The hearing officer kept going back to it.

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