"ootstra" uses Meta-Title and -Description for default OpenGraph Data used in `jonom/silverstripe-share-care`. Since the required lengths for title and description in both cases is pretty similar, the generated defaults many times just work out of the box.
ATM Elemental setup includes a default Hero from SiteConfig. Usually an Image gets set with a HeroElement per Page - if not the default Image is used. The first Image on the Hero is also the default OpenGraph Image unless set differently per Share&Care.
Same Data is also used for Teasers. On Home for example are tree posts linked. This is done with a FeedTeaserElement - not much needed rather than setting the parent, since Posts are "self-contained" - title, description, image & link are there. FeedTeaserElment in combined with categories or even multiple parents offers interesting ways for internal linking. The "self-contained" linking concept is reasonable simple an can be used for articles or whatever collections. Working with previews makes authors think about title and descriptions so basic SEO requirements are reached more integrative.