How on earth are you supposed to take 200+ pages of your work and condense it down to two or three paragraphs? Better yet, 300 words! Impossible, right? Wrong. It's done every day.
When I set out on the journey to write a synopsis, I did what anyone would do. I did some heavy duty research. I found website upon website, all giving the magical equation as to how to write a great synopsis. Let me tell you this, all it did was confuse the heck out of me.
Finally, I decided I was over thinking the whole process. When pitching a new story idea to my editor, I write out what I see happening from beginning to end. It's that logic I use to create my synopsis. And it worked! All of the stress I had regarding writing a brief to-do about my book disappeared. Now mind you, I still hate writing a book blurb, but when I look at it from the vantage point of writing to a friend, someone I trust, the task isn't so terrifying.
So, I've said all of that to basically say this...do what is comfortable for you. Don't freak out. Just relax and let your words flow. You're a writer after all, and writers write. It's that simple.