1. Check that you haven’t made one of the 7 common Magento SEO mistakes.
2. Make a good robots.txt file.
3. Strategically think about your site’s main navigation.
4. Implement schema.org microdata markup into your theme to display breadcrumbs, price, reviews and more in SERP.
5. Implement rel prev and next on your pagination.
6. If you have multiple languages, implement rel alternate hreflang x.