Planning campaigns, hunting down creative, editing the creative to fit social media platforms, planning daily budgets, working on audiences, etc., etc.: There are a million things that need to be done with each new campaign, so are shortcuts welcome? I say yes.
One of the ways that I save time and effort is building out Facebook saved audiences. These do take some time to build out initially, but you will be thanking yourself in the future when your client or boss asks you on a Friday afternoon to build out a campaign that needs to be launched by the end of the day.