OG meta tags
As part of your social media search engine optimisation make sure you have an OG graphic that will look good. By OG I don't mean "Original Gangster" or "Old Git" as per the web definitions but "Open Graph" as per the Open Graph Protocol used by facebook. At the very least you should have the four required properties in your source code to turn the page into a graph object.
og:title - The title of your object as it should appear within the graph, e.g., "GMB Web Designs".
og:type - The type of your object, e.g., "website"
og:image - An image URL which should represent your object within the graph.
og:url - The canonical URL of your object that will be used as its permanent ID in the graph
Put simply your OG meta tags control how your webpage information will look on facebook. Without them facebook will automatically gather together the information from your page and then display it. This may not be the best information to ensure your details are shared eg. the image displayed may not be the one that correctly reflects the page contents. It is important therefore to tell the social platforms what information to use. It also assists the other major social platforms such as twitter, linkedIn and Google+ as they use the OG protocol also. Twitter has it's own set of meta tags called twitter cards however if they aren't in existence it falls back to the OG meta tags.