Publish relevant and reliable content. Evaluate current keywords and trends regularly. By placing keywords in the headings, you indicate to search engines and users that your content meets the objective intent behind those search terms. Just as a table of contents provides context to users, keywords placed in headings can do the same with search engine robots.
If you're new to SEO or want to make quick and impactful changes, focusing your efforts on page SEO tactics is a good starting point. So, if you're providing services in a specific geographical area, local SEO is very important (perhaps even more important than “regular SEO”).