Critical Thinking...

Critical thinking is a form of judgment, specifically purposeful and reflective judgment. In using critical thinking one makes a decision or solves the problem of judging what to believe or what to do, but does so in a reflective way. Critical thinking gives due consideration to the evidence, the context of judgment, the relevant criteria for making that judgment well, the applicable methods or techniques for forming that judgment, and the applicable theoretical constructs for understanding the nature of the problem and the question at hand. These elements also happen to be the key defining characteristics of professional fields and academic disciplines. This is why critical thinking can occur within a given subject field (by reference to its specific set of permissible questions, evidence sources, criteria, etc.) and across subject fields in all those spaces where human beings need to interact and make decisions, solve problems, and figure out what to believe and what to do.

...wikipedia

Overcoming Bias

There is no simple way to reduce one's bias. There are, however, ways that one can begin to do so. The most important require developing one's intellectual empathy and intellectual humility. The first requires extensive experience in entering and accurately constructing points of view toward which one has negative feelings. The second requires extensive experience in identifying the extent of one's own ignorance in a wide variety of subjects (ignorance whose admission leads one to say, "I thought I knew, but I merely believed"). One becomes less biased and more broad-minded when one becomes more intellectually empathic and intellectually humble, and that involves time, deliberate practice and commitment. It involves considerable personal and intellectual development.

To develop one's critical thinking abilities, one should learn the art of suspending judgment (for example, when reading a novel, watching a movie, engaging in dialogical or dialectical reasoning). Ways of doing this include adopting a perceptive rather than judgmental orientation; that is, avoiding moving from perception to judgment as one applies critical thinking to an issue.

One should become aware of one's own fallibility by:

1. accepting that everyone has subconscious biases, and accordingly questioning any reflexive judgments.
2. adopting an ego-sensitive and, indeed, intellectually humble stance
3. recalling previous beliefs that one once held strongly but now rejects
4. Tendency towards group think; the amount your belief system is formed by what those around you say instead of what you have personally witnessed.
5. realizing one still has numerous blind spots, despite the foregoing

An integration of insights from the critical thinking literature and cognitive psychology literature is the "Method of Argument and Heuristic Analysis." This technique illustrates the influences of heuristics and biases on human decision making along with the influences of thinking critically about reasons and claims.