By far the most important thing by my opinion, is how to start the work. For me this is coffee. I start zipping it behind the computer, while reading support requests, or daily tech news.
Then I turn on terminal and run Gulp and I usually have a second terminal for other things. I use Sublime text, Google Chrome, SASS for CSS, GIT for version control. I use Local by flywheel and MAMP as a server solution.