Celebrity + controversy works well for me. This theme usually goes above average. Two years ago, I gave Umair & Jessica a poke in the eye: $68.00! It's almost sad this has been my "best" Medium article.

I developed a theme called "Three Articles that should have done better." Quick to write & publish.

https://medium.com/@davevolek/another-three-articles-that-should-have-done-better-45305d0f2259

Initially, these articles did quite well. Last couple didn't have much traction.