One - Find a good editor or beta-reader. You might consider yourself a good editor, however it really pays to have a different set of eyes check out your work.
Two - I don't care what anyone says - get your domain name. Even if you don't use it right away, it's good to have the domain ready when you have the time and resources to build the website. Domains are not expensive. Buy it and stash it away until you're ready for it.
Three - Start your marketing now, even if your book is not finished. How? Stop by your favorite book stores. Watch a published author do a book signing. Pay attention and learn. Find out how to use Twitter, Facebook, Instagram, Goodreads, and other social media platforms to your advantage. Sidenote: be patient. The marketing part of this takes a lot of time.
Four - Think about a critique group. I used one and the experience was one of the best ever. I was lucky to find a fantastic group of people. One went on to have one of her books made into a movie. More than thirty people were published after joining the group. Think about looking for a group in your area.
Five - Be consistant. Set a time and place to write. Stick to it. That is your time to write. The pages will come.