So I've worked with WP on many different occasions, but always either for a fresh install, or on a low-traffic live site with minor edits done in production.
I'm going to be working on an overhaul of a site that is currently live. What I'm doing is not only creating a new theme, but also overhauling almost all of the content. I'm essentially creating a new site on the same WP install.
If I was editing just the theme, I understand there are several ways to do this. However, for editing both theme and content while not disturbing a live site, what is the best way to go about this?