While you can often start with a keyword and create a piece of content around that term, sometimes your content already exists, and you need to figure out how to match it to keywords. To do this, create what's known as a "content to keyword map." Creating this map can help you understand the impact of your existing content and identify weak links or gaps that need filling.
I’ve always thought if you are serious about ranking – do so with ORIGINAL COPY. It’s clear – search engines reward good content it hasn’t found before. It indexes it blisteringly fast, for a start (within a second, if your website isn’t penalised!). So – make sure each of your pages has enough text content you have written specifically for that page – and you won’t need to jump through hoops to get it ranking.
Brand new keywords sound super tricky to find — except for a ton of easy ones that come around every January: simply adding the year to whatever keyword you’re targeting. People can start getting traffic from “2020” keywords long before they show up with any kind of search volume in typical keyword-research tools, since their data lags. (Hat tip to Glen Allsopp, who I got that idea from.)
So: how to proceed? On the one hand, SEO best practices recommend that you include relevant keywords in a number of high-attention areas on your site, everywhere from the titles and body text of your pages to your URLs to your meta tags to your image file names. On the other hand, successfully optimized websites tend to have thousands or even millions of keywords. You can't very well craft a single, unique page for every one of your keywords; at the same time, you can't try to cram everything onto a handful of pages with keyword stuffing and expect to rank for every individual keyword. It just doesn't work that way.