Option 1: They can be earned by progressing through the game.
Option 2: Press Crypt on your Homepage (or Action Bar), then scroll down to Favor Points. Once, there, press Free Favors to access special offers.
For missing Favor Points from offers, access the offers page as described above, scroll to the bottom of the Special Offers page and press Help.
Talk about this and other topics in our Community Discussion area ^V^