Ideas and Prose is an interesting post on "the disparity between thinking and writing". While I am not sure that there is a great disparity, the problem is worth thinking about.
Among other things, there is a claim that this disparity "is amplified in the case of having an idea in, say, Danish and writing it down in English." Not in my experience. (I am a native German speaker, who has lived in English for more than forty years. I usually do not know in what language I am "having an idea." In fact, whatever it is that "I'm having," becomes an idea only when I write it down or say it in English or German. Before I see it, I have no clear idea about "it" (no pun intended, of course).
To be sure, I can also clarify or "see" it "in my mind," but this is a secondary, not a primary mode of attention. Expressing the idea is a necessary condition of the possibility of "having" it. And writing is better than talking. (No matter what Plato might have thought—or should I have said written?)
Still, I agree with the conclusion that the "only proven method is to think often and to write often"—as long as it is understood that the two activities are not as disparate as some people think they are. Writing is the most effective “way of thinking,” if only it makes explicit what would otherwise remain mere musings.
1. See also On the gradual creation of thoughts while speaking.
2. I also found interesting the post on Dividing Your Time