So you have a new site. You fill your home page meta tags with the 20 keywords you want to rank for – hey, that’s what optimisation is all about, isn’t it? You’ve just told Google by the third line of text what to filter you for. The meta name=”Keywords” was actually originally for words that weren’t actually on the page that would help classify the document.
Google will INDEX perhaps 1000s of characters in a title… but I don’t think anyone knows exactly how many characters or words Google will count AS a TITLE TAG when determining RELEVANCE OF A DOCUMENT for ranking purposes. It is a very hard thing to try to isolate accurately with all the testing and obfuscation Google uses to hide it’s ‘secret sauce’. I have had ranking success with longer titles – much longer titles. Google certainly reads ALL the words in your page title (unless you are spamming it silly, of course).

“Sharability” – Not every single piece of content on your site will be linked to and shared hundreds of times. But in the same way you want to be careful of not rolling out large quantities of pages that have thin content, you want to consider who would be likely to share and link to new pages you’re creating on your site before you roll them out. Having large quantities of pages that aren’t likely to be shared or linked to doesn’t position those pages to rank well in search results, and doesn’t help to create a good picture of your site as a whole for search engines, either.
Use common sense – Google is a search engine – it is looking for pages to give searchers results, 90% of its users are looking for information. Google itself WANTS the organic results full of information. Almost all websites will link to relevant information content so content-rich websites get a lot of links – especially quality links. Google ranks websites with a lot of links (especially quality links) at the top of its search engines so the obvious thing you need to do is ADD A LOT of INFORMATIVE CONTENT TO YOUR WEBSITE.
There are a lot of definitions of SEO (spelled Search engine optimisation in the UK, Australia and New Zealand, or search engine optimization in the United States and Canada) but organic SEO in 2019 is still mostly about getting free traffic from Google, the most popular search engine in the world (and almost the only game in town in the UK in 2019):

For me, when SEO is more important than branding, the company name goes at the end of the tag, and I use a variety of dividers to separate as no one way performs best. If you have a recognisable brand – then there is an argument for putting this at the front of titles – although Google often will change your title dynamically – sometimes putting your brand at the front of your snippet link title itself. I often leave out branding. There is no one size fits all approach as the strategy will depend on the type of page you are working with.
In addition to processing the text content on your web pages, Google will also try to figure out what your images are about as well. Alt Text is a short description that you can customize for each image to let Google know what the image is about. Setting short, descriptive Alt Texts through our site builder will help Google better associate your web pages with the search terms you're trying to target.
Many search engine marketers think who you link out to (and who links to you) helps determine a topical community of sites in any field or a hub of authority. Quite simply, you want to be in that hub, at the centre if possible (however unlikely), but at least in it. I like to think of this one as a good thing to remember in the future as search engines get even better at determining topical relevancy of pages, but I have never actually seen any granular ranking benefit (for the page in question) from linking out.
An SEO technique is considered white hat if it conforms to the search engines' guidelines and involves no deception. As the search engine guidelines[18][19][52] are not written as a series of rules or commandments, this is an important distinction to note. White hat SEO is not just about following guidelines but is about ensuring that the content a search engine indexes and subsequently ranks is the same content a user will see. White hat advice is generally summed up as creating content for users, not for search engines, and then making that content easily accessible to the online "spider" algorithms, rather than attempting to trick the algorithm from its intended purpose. White hat SEO is in many ways similar to web development that promotes accessibility,[53] although the two are not identical.

Keyword analysis. From nomination, further identify a targeted list of key­words and phrases. Review competitive lists and other pertinent industry sources. Use your preliminary list to determine an indicative number of recent search engine queries and how many websites are competing for each key­word. Prioritize keywords and phrases, plurals, singulars and misspellings. (If search users commonly misspell a keyword, you should identify and use it). Please note that Google will try to correct the term when searching, so use this with care.