Update 04/20/2014: Adjusted to take into account the modular configuration layout introduced in strongSwan 5.1.2. Tweaked cipher settings to provide perfect forward secrecy if supported by the client.
This article is a step by step guide on how to prepare strongSwan 5 to run your own private VPN, allowing you to stop snoopers from spying on your online activities, to bypass geo-restrictions, and to circumvent overzealous firewalls.