In case you have no idea about the content a page should have but you have to write it anyway, because you client absolutly want it or because there is an obvious use for such a landing page but you have no inspiration on the content, I present you with a methodology to write a text about a given topic whithout prior knowledge:
Take the few first search result pages and use it as inspiration for the page structure and content. Once you have an overview of the different elements that needs to feature on the page. You will have a better idea on how to layout the page.
With the example gathered from to pages you can now write a text that presents your topic/product/category correctly, using appropriate keyword and satisfying customer expectation and ansewering customer intent.
Even if the pages you use for inspiration or as source were ranking well they might be overooking important keyword or not be fully satisfying for the customer. So don’t hesitate to take further step in order to write better text using a more engaging layout.