Watch this 15min video in which I explain in detail how you can get your Full-Funnel Retargeting right by really tackling everyone in your potential audience:
This should always be the first step in order get positive ROAS on your Facebook Campaigns.
In order to have profitable Prospecting campaigns up and running you need to have a clear AB-Testing Structure in place.
Without testing at least 2 times per week (Monday & Thursday) a series of new Outreach Audiences, you wont find a profitable Ad Set.
So, start with analyzing and profiling your own Buyer Persona and then apply these learning to the Facebook Algorithm.