The best way are signature campaigns but you can also offer services and earn a lot. My record is 90$ in one month. Good luck! 
This is quite decent to earn as a result of posting on a forum simply by expressing opinions on matters based on your perceptions and thinking. How I wish I can earn more of that but I know with time though not easy to really earn from signature campaign one needs to really rank up. Because even going through various campaign a Legendary rank member could earn like 0.04btc which is like $24 on a $600 range and with that multiply by 4 weeks is really something. As for me in my rank now, Im really earning low.