The 'Facebook Best Practices' graphic from Passion Digital is an extensive one that provides tips for what's it calls "the king of social networks." With over 11.5 billion users, it's pretty clear that Facebook is still a force to be reckoned with, if you know how to take advantage of it.
The infographic advises posting about once or twice a day, with a three hour gap in between to allow for maximum engagement. Posts that are short and sweet and use photos are also proven to get higher engagement as well. Passion Digital also advises taking a peek into the analytical insights that Facebook offers to understand when your audience is most interested, since social strategies will vary from business to business.