To find your own secret keyword formulas, open up your analytics and look at the headlines and keywords from your site’s all-time best (or recent best) traffic-driving content. See any secret formulas?
SEM Rush has a cool feature that allows you to see what keywords your competitors rank for, including keywords where they’ve earned the coveted featured snippet. To find this info, type in a website address in the Domain Analytics tab, then expand the organic rankings report and click “Featured snippet” under “SERP Features”