Add Social Media account linking in the Alexa App for all skills to use
Allow users to link their social media accounts (Facebook, Twitter, Instagram, etc) in the Alexa App itself. Then allow skills to query which accounts are linked and request permission to use those links, without requiring each skill to perform account linking separately (and perhaps not even exposing the account details to the skill, for greater privacy!).
This would allow a skill to request permission to post to Facebook, for example, to share their new high score. The skill would request this permission at the time of the interaction, and the approval would be delegated to Amazon's built-in handling (to make sure the skill did not deceive the user into granting permission). Once permitted, the skill would be able to use an Amazon API that would in turn call the social media API.
This would abstract this common interaction away from each skill, provide greater consistency, and encourage organic growth of skills.