I used to think it was a simple as using the sunscreens with metals in them to reflect the sun and the whiter you look, the more effective, but it looks pretty complicated when I did more research on how UVA and UVB are blocked.
For one, it seems legislation to study the ingredients in the US was only passed Nov 2019. Even the size of the titanium and zinc particles affects the effectiveness.
The Mayo Clinic link is probably the best summary, to just use something and avoid peak sun hours. But it seems the non metal sunscreen ingredients are also important to project via absorption.