The first step into creating good habits is figuring out why exactly you want the habit. To me, writing blog posts seems like a good habit, but I'm unsure why. This post will attempt to convince the reader and myself of the benefits. I have combined my own ideas with the ideas by Terry Tao  and Gregory Gunderson , and grouped them.
Writing detailed expository notes is a way to practise research. This allows you to break free from the methods you are used to .
One can practise writing .
Writing allows one to test understanding of an idea . It forces you to explain it clearly without hand waving. When aiming your text at colleagues or future employers, you cannot use jargon to hide your lack of knowledge .
Writing allows figuring out what exactly you do not understand or what you need to learn first .
Writing aids in structuring knowledge .
Writing a post might not actually solve some difficult problem, but it is a concrete step towards a solution . It will probably teach you a lot about the background of a problem.
Good ideas do not randomly appear. They are formed after getting a deep understanding of the problem .
Information can be recalled easily [1, 2].
Writing frees up mental space .
It eases sharing information with friends and colleagues.
Much (scientific) knowledge, which someone in this world has, is not known to the public. Writing technical blogs can help to spread information .
Others can inform you of mistakes in your thoughts. See the post by Swartz  for more about better thinking.
Compared to papers, blogs are read by more people.
By now, I hope the reader is convinced. I have, at least, convinced myself.
 Terry Tao. (2009). Write down what you've done. Retrieved January 16, 2020, from https://terrytao.wordpress.com/career-advice/write-down-what-youve-done
 Gregory Gundersen. (2020). Why I Keep a Research Blog. Retrieved January 16, 2020, from http://gregorygundersen.com/blog/2020/01/12/why-research-blog
 Aaron Swartz. (2006). Tips for Better Thinking. Retrieved July 29, 2020, from http://www.aaronsw.com/weblog/thinkbetter