Rustation

I've been using macOS as my daily driver for over 11 years now - since just before the Intel switch.  I've been getting back into Windows for the sake of PC gaming and VR a bit lately, but still prefer macOS for getting most of my work done.
 
Off the top of my head, here's what I can think of that any new Mac user should know:
Many useful little apps in the Utilities folder (under Applications).  I use things in the Utilities folder so frequently that I've added it to my Finder sidebar Audio MIDI Setup - configure weird and wonderful audio behaviours Console - view system debug messages Digital Color Meter - measure on-screen colours Terminal You can drag a file from Finder into Terminal and it will paste the file's full path If you have spent much time using Linux, FreeBSD, or other unix OSes or want to learn any development, you should install a package manager like Homebrew, Macrpots or Fink I personally prefer Macports, it works similarly to BSD and Gentoo Ports style packaging.  It has a very large collection of packages that install reliably Homebrew is a unix-like package manager designed for macOS specifically.  It's the most popular in the community at the moment Fink provides debian-like packaging.  It is less popular so doesn't have as broad a base of packages as other tools, but the essentials are there.  Unlike the other two, it downloads binary packages so installs should be a lot faster. Spend some time clicking through every option in System Preferences - macOS gets thought of as an operating system where Apple dictates their opinions to you, but actually there are a lot of little customisations you might like to make that might work better for you Two UI tweaks I like to make are under General - "Use dark menu bare and dock", and also I like to change the text highlight colour Download Xcode from the App Store, then register for free at developer.apple.com, then download the "Additional tools for Xcode".  This includes Quartz Composer which you can use to make your own screen savers without writing code You can fill in PDF forms with the built-in Preview - even forms that were not designed to be fillable - using Tools -> Annotate.  You can even save an image to user as your signature There's a built-in print-to-PDF button in the bottom left corner of the system print dialog.  Whenever I use Windows I'm annoyed by this not being a built in feature That's all I can think of for now.  I'll add to this thread as I think of more.