Overall, I think the best trading and investing comes down to being able to recognize when there is a significant disconnect between price and value, and knowing how to take advantage of this disconnect.
This is something I've been forced to recognize lately. As a complete amateur, I felt very wise when I learned about it.
I'm into four very distinguished currencies/commodities and I'm finally understanding why something is happening and what I should do about it. It's making a lot of difference.