Being able to have alternate light sources apart from your flashlight and fire will be a major asset when SHTF. It will allow you to, say, light a route to your toilet (AKA hole in the ground) or read your maps or books when your batteries run dry. Learn how to make a primitive birch oil lamp in the video below.

A primitive oil lamp is probably one of the most reliable light sources you can have. It will be easy to keep loaded up with fuel, as birch trees grow in large clusters and can often be found lying on the forest floor in droves.

It also lights up even when it's raining, so all you need to do is protect the flame from the wind.