Everyone has their method, and obviously, as you gain more experience and have more work published, you should naturally develop a system that works for you, similar to developing a writing style. I would read through all the responses in your thread, and pick and choose from there what you think works for you.
My style of writing when it comes to the actual writing process, I write what I feel and I tend to read back what I wrote at least one or more times and make edits as I go. Once I feel I have the entire manuscript the way I want it, I print it out and read it through, red penning as I go using proofreader marks, as my background is photojournalism, so I'm a more AP Style Guide, guy. Sometimes I may print a chapter that I wrote, go outside or to some other environment just around the corner, just to read in a new light source or ambiance.
I will then red pen edits, enter the edits, and may print it out again, but only that chapter/section I'm working on at the time. I also travel a lot, so when I travel, I will have printed out the entire manuscript completed so far, because I feel it's important to start from page one and read all the way through, red penning along the way, so if I stumble on ideas or feel I need to add more, I can make red pen notes along the way, besides the edits.
I don't count the rounds, I do look at word count, but more important, I look to see if I've completed what I truly want convey in my non-fiction books. I do believe editing on paper with a red pen will help you find things that editing on screen you might not catch.
Along the way, I have a few trusted friends, some with real editing experience, that I will send the manuscript, regardless of the stage of completion and ask them to provide their edits/feedback. When I get that feedback/edits back, I then decide how much of their edits I want to use or not use. Sometimes those editors might come up with things I didn't think of to add more content to my book. I like to call it my focus group and it's composed of both male and female, sometimes you want the different perspectives of the genders.
I hope that helps, and good luck with all your writing endeavors. Rolando