Practical Advice

How can we counteract these cognitive biases we're learning about?  Examining the way we think and becoming more aware of our biases is a good start, but is not in itself a solution.

One big point is to own our fallibility. Awareness of our limits and biases should lead us to lower our degree of confidence in many of our beliefs--particularly deeply held opinions and stances on controversial issues. Simply put, we should get in the habit of admitting (and sincerely believing) that there's a real chance that we're wrong.

Here are two other big, simple points I think make for some great practical advice:

1. Get Unfamiliar! Actively seek out sources that you disagree with. We tend to surround ourselves with like-minded people and consume like-minded media. This hurts our chances of discovering that we've made a mistake. In effect, it puts up a wall of rationalization around our preexisting beliefs to protect them from any countervailing evidence.
2. Focus on What Hurts! When we do check out our opponents, it tends to be the obviously fallacious straw men rather than sophisticated sources that could legitimately challenge our beliefs. But this is bad! We should focus on the best points in the arguments against what you believe. Our opponents' good points are worth more attention than their obviously bad points. Yet we often focus on their mistakes rather than the reasons that hurt our case the most.