The label is overused. Plenty of content that calls itself thought leadership is opinion without evidence, or a summary of what others have already said. The real thing has a specific point of view, and it is useful enough that people act on it or pass it on.
It is a long game. Thought leadership builds through consistent publishing on a few subjects, in posts, articles, newsletters, talks and interviews, and through the conversations it starts. For founders and executives, it often does more for a company’s reputation than the company’s own channels, because audiences tend to trust people more readily than brands.