I think accuracy in prediction happens when you're exposed to a lot of information in aggregate over a long period of time. You begin to see attitudes change and trends unfold at their earliest stages, sometimes even beforehand (backlashes to a popular concept for example).
It's more subconscious than conscious. You just have to let all this information wash over you. There's no way you can mentally grapple with it all.
Even if it's subconscious, if one could come up with a way to measure this "accuracy in prediction", I think it could be trainable.