I believe that the first way to avoid getting scammed is not being greedy and believing in something for nothing, secondly not seeking the easy way to achieving a great financial success.
You nailed it with those two statements. If you check very well, the majority of the people who fall into the victim or scam were because of their greed and the belief that there is free money out there. Once you are greedy and want free things, then you become the number one target for scammers. They will sell that idea and information that you so much hope and desire for to you, and you will end up buying and believing it without even giving it a second thought because that's exactly what the person was expecting.