If I had more time, this letter would have been shorter. -- Mark Twain
I'm more of an editor than a writer to be honest. Because of that, my process is quite detailed. I could write an essay right here describing what all I do and why.
I will not.
You are welcome.
In a nutshell, I start with a verbose rough draft in which I've already included everything I might want in the final. Then in the first pass, I cut out large unneeded pieces, rework substantive changes like events and jokes, and change whatever spelling or grammar mistakes I happen to notice. The second pass is all about details. I cut unneeded individual words, reword sentences to make them tighter or more clear, and read each libe twice looking for typos errors. Sometimes I'm satisfied at that point, and sometimes it needs additional passes.
Lastly, I get another editor to make a final pass whenever feasible, because editing ones own work is never very accurate.