Hello @artguru
Great topic for reasoning. Indeed one of the most important factors of a successful blog is the topic. The right theme can bring success. But there are a number of factors on which the user is looking for a topic for his blog. And the main one in my opinion is that the blog would help people.
You perfectly diversified the theme with the example of shoes.

When your `shoes’ fit the bill, their needs, you have a foundation to build on.

these are the right words, you need to choose the right shoes
I visited your site, I like your work. It is very beautiful and picturesque, but the main descriptions that complement the picture.