If you link out to irrelevant sites, Google may ignore the page, too – but again, it depends on the site in question. Who you link to, or HOW you link to, REALLY DOES MATTER – I expect Google to use your linking practices as a potential means by which to classify your site. Affiliate sites, for example, don’t do well in Google these days without some good quality backlinks and higher quality pages.
Repeat this exercise for as many topic buckets as you have. And remember, if you're having trouble coming up with relevant search terms, you can always head on over to your customer-facing colleagues -- those who are in Sales or Service -- and ask them what types of terms their prospects and customers use, or common questions they have. Those are often great starting points for keyword research.
NOTE, in 2019, the HTML title element you choose for your page, may not be what Google chooses to include in your SERP snippet. The search snippet title and description is very much QUERY & DEVICE dependant these days. Google often chooses what it thinks is the most relevant title for your search snippet, and it can use information from your page, or in links to that page, to create a very different SERP snippet title.

SEO techniques can be classified into two broad categories: techniques that search engine companies recommend as part of good design ("white hat"), and those techniques of which search engines do not approve ("black hat"). The search engines attempt to minimize the effect of the latter, among them spamdexing. Industry commentators have classified these methods, and the practitioners who employ them, as either white hat SEO, or black hat SEO.[50] White hats tend to produce results that last a long time, whereas black hats anticipate that their sites may eventually be banned either temporarily or permanently once the search engines discover what they are doing.[51]

While the title tag is effectively your search listing’s headline, the meta description (another meta HTML element that can be updated in your site’s code, but isn’t seen on your actual page) is effectively your site’s additional ad copy. Google takes some liberties with what they display in search results, so your meta description may not always show, but if you have a compelling description of your page that would make folks searching likely to click, you can greatly increase traffic. (Remember: showing up in search results is just the first step! You still need to get searchers to come to your site, and then actually take the action you want.)
Basically, SEO keyword research should be an ongoing and ever-evolving part of your job as a marketer. Old keywords need to be reevaluated periodically, and high-volume, competitive keywords (or “head” keywords, as opposed to long-tailed keywords) can often be usefully replaced or augmented with longer, more specific phrases designed not to bring in just any visitor but exactly the right visitors. (Who visits your site – particularly if they’re people who are actively looking for your services – is at least as important as how many people visit.)

Submit website to directories (limited use). Professional search marketers don’t sub­mit the URL to the major search engines, but it’s possible to do so. A better and faster way is to get links back to your site naturally. Links get your site indexed by the search engines. However, you should submit your URL to directories such as Yahoo! (paid), Business.com (paid) and DMOZ (free). Some may choose to include AdSense (google.com/adsense) scripts on a new site to get their Google Media bot to visit. It will likely get your pages indexed quickly.