Very sparse on the words here, but Britannica gives some actionable tips on improving curiosity.

An article with active steps you can take to be more curious (that DOESN'T cite the Ian Leslie book!)

This is another article on curiosity that mentions - and paraphrases from, without citing - Ian Leslie's Curious, a book I am still not sure I like.

I've bought and begun reading the book mentioned in this article, and it seems like this article is simply a summary of the book - complete with intensive quotes (MOST of the article!)

I'm a little disappointed with the book so far - I'm extremely disappointed by this "article".