Its pretty simple. Get the sigil from Variks and have a healthy amount of 3oC, pop two House of Judgement rep boosts and head to the CoE. Once there use 1 3oC for every boss fight. After finishing the round simply reload the activity in the director and repeat ( I've heard rumors that the longer you do the same activity the better the rewards). Using this method, through a combination of the reputation rewards from Variks and infusions from the Exotics dropped I've managed to raise two of my characters past 330 light in the matter of a month. Good luck to all those trying to level, i hope this works for you as well!