Spend a little time every month refreshing and updating your website content to help drive higher ranking in Google.
Why? The search engine reward quality webpage content, so if you keep the focus on that your rankings should improve over time. Google talk about providing a great page experience in their own search documentation.
The important thing with this is not to just change things for the sake of it. Think about how you can improve a web page and make it more useful and valuable to your visitors.
What to learn more on this topic? I've written a full blog post on how refreshing website content can aid ranking.