Meta keywords are those keywords that are mentioned in meta keyword tags. These keywords are useful and specific to website to website and business to business.
For Title tags, see in google search how many characters you see it shows when you make a search in it. It is generally 50 to 65 characters with black spaces. In descriptions there should be 170 to 180 character including blank spaces.
Doing white hat seo for both on page and off page is quite useful tip for seo of a site. Be natural and give attention to good tittles, descriptions and content of a website.
You should have a large circle of friends and clients on social media sites to get benefits of it. Secondly your information that you share should be shared and important for sharing purpose.