Search engine spiders can only spider through text. They will use the content on your site to determine what your site is about, which in turn will help to decide how highly your site will be ranked for specific keyword phrases when visitors type them into the search engines. For this reason, keyword research is critical to obtaining natural search engine placement and should be at the top of your list when mapping out your SEO strategy.
Users will occasionally come to a page that doesn't exist on your site, either by following a broken link or typing in the wrong URL. Having a custom 404 page30 that kindly guides users back to a working page on your site can greatly improve a user's experience. Your 404 page should probably have a link back to your root page and could also provide links to popular or related content on your site. You can use Google Search Console to find the sources of URLs causing "not found" errors31.
We now have a dedicated SEO strategist who, among other things, develops 90 day plans for our websites. 90 days isn't longterm planning, but at least we have a strategic objective for the quarter. He also works closely with our UX team to identify the target audience - the crew that does the persona research and focus groups prior to the wireframe stage.
I completely agree that defintion of a target audience isa great first step, but would ask if adding in competitors to the analysis (mentioned here as a later step) helps draw out who your target audience would be via comparisons, i.e. showing who you are an who you are not - would be very interested to hear opinions on how this tactic can be used within the overall step in coordination with targeted keyword discovery.