After having to set up my laptop a number of times after repeat visits to the Apple Store, I got tired of manually changing setting after setting to set up my environment. This script is the result of my frustration.
To run the script, first read through the init.sh file. It's changing a lot of things, and while you may not understand it all, it shouldn't be too difficult to see what's going on. Some of the options have values that you can tweak to your liking.
After you've read through init.sh, open terminal.app by going to Finder > Applications > Utilities > Terminal. When it loads, just drag init.sh into the window, and hit enter. The script will first prompt you for your computer password. Then, it will ask for a bit of information. Nothing is being stored, so no worries about where your info is going.
tl;dr: run init.sh in terminal. follow the prompts.
Feel free to make a pull request with any new options you want to see, or just open an issue if you think of something you'd like to see, and I'll do my best to make it an option.