from what I've read about making an effective synopsis, you centre it around your MC. They are to be the most compelling person in the entire novel. What happens to them, how it affects them, what they do to overcome it. Those are the things you focus on.
a good piece of advice I came across is to write the hook for your book, the one sentence that seems it up. this is where your synopsis will start. Then write one sentence that perfectly describes the end. Study those and figure out the key centre/climax to your book. Write one sentence about that. as you build from the beginning hook, to the centre, to the end, you work at it until you've stripped the unnecessary details.
hope this helps somewhat. just focus on the MC though
