Three Essential Rules for Writing a Novel

Years ago I was privileged enough to hear the charming T.A. Barron speak. Holy Hannah! That man can captivate an audience.
If I remember correctly, he began his keynote address with these words, “There are three essential rules for writing a novel.”
Of course, he had us on the edge of our seats.
“Unfortunately, no one knows what they are.”
The auditorium filled with laughter. It’s true! What ARE the essential rules for writing a novel? There are as many methods and advice and rules as there are writers searching for them. 
But I stumbled across an essay in which T.A. Barron speaks of what he does see as essential for writers. 
He said we should:
#1: Observe
Pay attention to the world around you! Observe how your food tastes and the fall feels like and the people you pass sound like. Take it all in and then put it into your work. 
#2: Believe
This one can be tricky. But you need to believe in yourself. Believe in the stories you are creating. Believe you have something important to say. 
#3: Be disciplined
If you really want this to work. If you really want to be a writer. If you really want to finish that book….then you need to do it. You have to find the time. You have to make it important. Even when it’s tough. 
Years ago I heard someone say (and I wish I remembered who it was so I could give them the credit) something like, “Your worst words written are better than your best words never written.”
Interestingly enough, T. A. Barron did mention the three things he needs to write a story.   I stumbled across an interview he did where he said, “All I know is that, to craft a story, I need three things: a character I care about; a wondrous, magical place; and a troubling question or idea. Without those three elements, I simply can’t muster the energy to spend a day writing or revising a page—let alone several years creating a trilogy.”
So, maybe there aren’t three essential rules, but I love his three essential ingredients for writing a novel.
What do you think the essential rules or ingredients for writing a novel are? 

Erin Shakespear writes middle grade fantasy full of quirky creatures, magic, and strange adventures. With six kids, her days are full of quirky creatures, magic, and strange adventures, and…loads of diapers. She also likes to dabble at photography, sewing, jewelry-making, and pretending she’s a grand artist. She is the southern Utah coordinator for the Society of Children’s Book Writers and Illustrators.