How to use it
One clear subject, proper light, sharp focus, a clean background. No screenshots as the main image. Invest in a tripod and a cheap light before gear. Faces aren't a guaranteed boost on Instagram.
How sure we are
S Evidence: strong. Large trials or many studies, pointing the same way.
P Evidence: promising. Good studies, but small or few. Use it and keep checking.
Sources
Li & Xie 2020 (large datasets with causal-inference methods).
Not medical, legal or financial advice.