Be critical of but not brutal with your writing. If something isn't essential, get rid of it. Remember that good dialogue can serve a whole passel of purposes in your novel, and to overlook one of them is to overlook one of the tools of the craft. Like hitting a nail with a screwdriver, if you know what I mean.
Write Away: One Novelist's Approach To Fiction and the Writing Life (ed. Hachette UK, 2011) - ISBN: 9781444717600