Keyword density stopped being a useful target more than a decade ago. What search engines reward now is whether your page resolves the question behind the search — completely, and faster than the alternatives.
Start by reading the results page, not the keyword tool
Before writing anything, search your target term and study what already ranks. The format of the top results tells you what searchers want. If the first page is all comparison tables, a long essay will not break in. If it is step-by-step guides, a product page will not either. The results page is the clearest brief you will ever get.
Identify which of the four intents you are serving
Every search falls into roughly four buckets: informational (how does X work), navigational (take me to X), commercial (which X is best), and transactional (buy X now). A page that mixes intents serves none of them well. Decide which one your page owns before you write a sentence.
Answer the question in the first hundred words
Do not build up to the answer. Give it immediately, then explain, qualify, and expand. This serves impatient readers, and it is also how featured snippets get sourced. A page that buries its answer under four paragraphs of preamble loses on both counts.
Cover the questions the page raises
Look at the "People also ask" box and the related searches at the bottom of the results page. Those are the follow-up questions your reader will have. A page that answers them in place removes any reason to click back to the results — which is exactly the behaviour search engines are measuring.
Write for the skimmer and the reader at once
Descriptive subheadings, short paragraphs, and genuinely useful tables let someone extract the answer in twenty seconds. The full prose underneath serves the person who wants depth. You do not have to choose between them.
Demonstrate first-hand experience
Original numbers, screenshots from work you actually did, and specifics that could only come from doing the thing are what separate a useful page from a competent summary of other people's pages. Generic advice is now abundant and free; specifics are not.
Set a real update cadence
Rankings decay. Put a calendar reminder on every important page — quarterly for fast-moving topics, twice a year otherwise. Update the numbers, remove what has aged out, and add what has emerged. Refreshing a page that already has authority is consistently cheaper than earning it for a new one.
A brief you can reuse
For every page, write down five things before drafting: the primary intent, the format the results page rewards, the answer in one sentence, the follow-up questions to cover, and the specific evidence only you can provide. If you cannot fill in the last one, the page probably is not worth writing yet.