Analyze knowledge that is in front of you. To become a good thinker, it is important to never accept things without first questioning them. Display a healthy level of doubt when you initially encounter information. Look for ample evidence and supporting claims that can help you understand why and how something is the way it is instead of simply accepting everything that you read or hear.
Absorb details. When taking in new information and ideas, do not skim through things. Become detail-oriented and do not let anything (even if it seems rather trivial or minuscule), get past you. Knowing details can provide you with depth in your critical thinking process.
Pose questions. Having an inquisitive and curious nature is integral to being a good thinker. Learn about something from different angles by asking relevant questions. If you experience doubt or confusion regarding a subject, do not be afraid to ask. Remember that when you get a clear response to your query, you become that much smarter.
Set high expectations of yourself. When thinking or trying to come up with a solution to big problem, refrain from complacent behavior. Act as your greatest critic by questioning yourself. Ask yourself if you think that you can do better. Ask yourself if what you have done is truly to your best ability. Push yourself and your thinking to the limit as much as you can.
Evaluate the effectiveness of what you are doing. When you are working on something and notice that something just isn't right, take time to analyze the situation and figure out what the missing link is and what needs to change. Use these times as an opportunity to tweak your goals and desired outcomes, if necessary.