To be rational, you must change your view of things and your behaviour, and this task takes a little time, nevertheless here are three ways that will help you become rational: 
Think rationally and logically. To be able to think rationally, follow the following tips:

Accept the challenge for the development of your rational thinking: 
At first, you have to change the way you process events and think about them as well, and see this change as a challenge or an opportunity for development, and for the development of your rational thinking, your thinking must be more focused and logical using experience, facts, and research to take appropriate decisions.  

Confront your cognitive biases: 
You need to be honest about your cognitive biases, and to become a rational person try to express your own opinions and find rationales to support them and avoid any tendencies that may detract from your wisdom or ability to think rationally. Try to think objectively and impartially and confront your cognitive biases with them first and then change and overcome it.
Develop a system to improve your rational thinking:  Start to develop a clear plan to achieve what you want, for example, you can use a special notebook to write down the situations you have encountered and record your analysis by evaluating those situations, and record everything you thought at the time, how you reacted, what you learned about yourself and what things could be done. Change them and how think about how your response can make sense. Practice this strategy when facing problems as well.
Why should you be rational?  
Rational thinking brings you many benefits and features that are reflected on your mental health, and for this you have to have a rational personality and develop it. Following are some of the benefits of rational thinking:

1. Rational thinking avoids extreme thinking and thus avoids succumbing to the extreme feelings of emotional people. 
2. Rational thinking allows you to accept the imperfections of things. If you are a rational person, you know that there is no complete success without failure, and no partner is perfect without flaws, so you will be able to think logically, without letting emotions control you.  
3. Rational thinking is realistic and based on objectivity, you can confirm this by noting that the things and beliefs that bother you often have a weak relationship with reality, and therefore they generate emotional feelings and thoughts that are far from logic, reason, and reality.  
4. Rational thinking is scientific thinking that helps you to adopt a different perspective that accepts the current circumstances and considers solutions as well as ways to make the situation better, in addition it makes you more compatible with what is happening around you, and therefore you will try to improve reality in relative degrees based on logical solutions instead of the possibility of things deteriorating if you were an emotional thinker.
5. Rational thinking allows you to ask questions and improve in the future and adapt means to ends, which you cannot do with emotional thinking.

* The author is a consultant in Public Relations and Personality Types. Instagram: @Tipsbyhalahill