I do zero promotion, but that is mainly because I'm not here for the fame of it. I do it for fun. Those who wish to read my story will find it. Those who enjoy it will join my journey.
As for timing- find your audience. Timezones are the key. Post when the individuals you want to read your book will be active. Note when high posting volume happens and try to post before or after, lest your own release get buried.
Lastly, be consistent. Put a time and day in your book description. Let your readers know when to expect a release. That way if they miss it, or if someone randomly finds your story, they know when to check in to view the next chapter.
If you're going on hiatus, make sure to notify our readers as well. They'll appreciate the heads up and won't be so upset if you miss a release.
Be well,
-- J.C