Answer the question in the first two sentences rather than building to it. Ordinary writing can establish context and arrive at the point. A page found through search is landed on by somebody with a specific question who will leave if the answer is not visible, and systems extracting answers take what is near the top. The essay structure of introduction, development, and conclusion works against you here.
Use the words your readers use rather than the words your industry uses. This is where most professional writing fails, because the correct technical term is frequently not what anybody types. If customers say pipe leaking under sink and the industry says supply line failure, the page should contain both, with the customer phrasing in the heading.
Structure it so it can be scanned. Headings that describe what follows rather than being clever, short paragraphs, and one idea per section. This helps readers, who scan rather than read, and it helps machines identify which portion of a page answers which question, which is what allows a section to be surfaced on its own.
The habits that no longer work are worth naming because they persist. Repeating a phrase at a target density, writing eight hundred words when four hundred would answer it, and stuffing variations into the text all made sense against systems from a decade ago and now produce material that reads badly and is recognised as thin. Length should be determined by the question rather than by a target.
The largest difference between writing that ranks and writing that does not is specificity: numbers, examples, and detail that could only come from somebody who does this work. That is also what makes writing worth reading, which is why the two goals converge more than the terminology suggests.
Write the title and the description as deliberately as the page itself, since those are what appear in the results and determine whether anybody clicks. A page can rank well and receive almost no traffic because the title describes the topic rather than the answer. Treat them as the advertisement for the page: state what the reader will learn, in their words, within the length that will actually display rather than being cut off.