FC'ing the hardest that you can FC is always the best way to rank up, whether in PP or ranked score

play the hardest maps.
with mods.
and good acc.
and the maps should also be rather popular.

I believe its calculated based of how many ranked scores the map has in comparison to where you placed in that group, with what difficulty the map has, accuracy and mods you used as multipliers for how much pp you'll gain. Although both of the latter will get you a better spot, so in any case its simply "get good ranks on popular maps", but also just good ranks in general.

good ranks

good ranks

My answer is still the best one, disregard everyone else except me.

I am the greatest.

it's top 500, but the higher you are, the better.

Scoring well on hard and popular maps, getting as high up as you can, and if you're using difficulty increasing mods then you'll get a tid bit more pp for it.

be good at the game.

Don't care about the rank and play for fun ? :>