I have more experience with tumblr since it’s really easy to be found thanks to tags
Generally Nintendo franchises are a goldmine they’re popular between all type of people therefore more likely to share it, something like Pokémon which gen 8 is right around the corner and will explode soon so I suggest drawing a comic/fanart if the soon to be shown new Pokémon as FAST as possible
People tend to look on social media as soon as they announce anything
Shows/games with big OC potential are also good like splattoon, Pokémon, SU and ect. Theses are more likely to commission you and if they like you enough will keep coming back.
Anime commissioner in my experience had always been more picky/cheap so I tend to avoid those and furry commissioners are more likely to keep coming back and giving tips the bad part is that they expect to becoming friends while describing why pregnant wolves makes them hard.