I believe critical thinking is of high importance in our study, especially for doing research.
Critical thinking is, in my view, a kind of habit to think under the surface, when you have collected some information; you need to select, to choose and to decide which one is right, which one is suitable, and what improvements you can do to enrich them and to make them better.
To obtain critical thinking ability, you need to do the following aspects,
Firstly, know exactly the questions you are researching for.
Secondly, try to collect as much information as possible.
Thirdly, point out your explanations according to those theories.
Fifthly, make hypothesis and analysis them.
Lastly, do not make too easy conclusions and think more deeply.