1. If your main character wouldn't see or notice something don't describe it.
2. Readers want to live in the moment with the character - show don't tell.
3. Give your character two to three lenses through which he/she sees the world. (e.g. In CATALYST by Laurie Halse Anderson the protagonist sees the world through a scientific lens. "Toby and I are the proton and neutron of our atomic family unit.") The language develops because of the lens.
4. Study HOW TO READ NOVELS LIKE A PROFESSOR by Thomas Foster.
5. Interview your characters. Ask them, "Are you alright?" Though it sounds weird, Kathleen Duey swears by this.
I'd love to hear additional novel writing tips. So leave a comment and let's discuss.