Opinions vary about whether & how much you should plot out any piece of writing. Planning can save a lot of problems, but it can also kill the spark of originality. If you over plan the project you might find that by the time you come to make a start you are bored with the whole thing.
After all, a novel is a work of art, not a practical thing like a trip to Ikea.
The snowflake method sounds like an interesting approach. If you have tried it I’d be interested to know what you think.
Visit my websites via the links at the top of this page.