The short answer is to do everything the same like you do for SEO audits.
Start by identifying the words and phrases that your customers are searching for online, and update your website copy to better reflect those words and phrases. If you sell pizzas, make it easy for Google to understand that your website is about pizza.
For more advanced SEO, try working with any of the following keyword research tools to identify the greatest keyword targets for your business: Ahrefs (paid), SEMrush (paid), Google's Keyword Planner (free), and Moz (paid).
Add these words and phrases to your header tags, title tags, alternate text, inlinks, etc.