Some tweaks to my OS X shell (Terminal.app) that I've found useful.
I opted to install Grav via the ZIP package, as documented here. My hosting provider does not give me shell access, so I would not be using git or the Grav Package Manager (GPM), but limiting myself to FTP or the cPanel File Manager.
Apache and PHP 5.5.27 are installed already in OS X 10.11 El Capitan, so just a little enabling is required.
Updated 12 Oct 2016: See the slightly updated guide for macOS 10.12 Sierra, which has been updated to Apache 2.4.23 and PHP 5.6.24.