Want to start journalling / writing my thoughts – any tips?

Quite often here, in one context or the other, HN users mention they journal and write daily / regularly. This question might have been raised already, but I never came across it here.

This is always said to be a nice way to enhance your thinking, make your mind more coherent, have a better life and what not.

I kind of get the idea on a subconscious level, and I want to include this practice in my life, to better understand my thinking and help me being present, but I struggle to understand where to start.

I am not a writer, and I don't have so many events happening every day as to have a meaningful thing to write every day.

I do like note taking when I stumble upon interesting things, and I have all kinds of lists in my notes (facts, quotes, movies, books), but I want to have this as a more integrated practice and put my thoughts, not just facts I want to remember.

I also quite often see people mentioning Obsidian as a tool (I usually use Apple notes, but having installed Obsidian I really like the UI and wanna give it a go).

So - do you have any tips on how to set my mind and understand the purpose of writing intuitively (as opposed to subconsciously) and start practicing it?

Thanks to everyone in advance.