Then just do it everywhere you can, because if you’re busy, that begets more work. There’s not any real science to it, but it seems if you’re busy, you get business. So do free work for people (but don’t accept ‘requests’) - just do the free images for other people of their popular OC (if they permit it) until you have a body of images done that are in the franchise and will attract attention. Search for this string to find the most popular OC only images made so far this year:
oc only,created_at:2019,safe
Then check with the creators of the OCs (look at the tag of the OC to see if the detailed description shows the creator) and find out if they’re ok with folks doing free work of their OC, and if they are (even if that might come with some restrictions as to the kinds of art they’re ok with) then you’ve got a bunch of free work you can do to build a base in the franchise, and if those end up being popular images too that can attract a lot of attention to your profile and your commissions offerings.
Getting listed on Equestria Daily can give you a boost, but it’s hard to arrange that - you just have to be lucky and happen to have the image that they’re looking for when they look for it.
And be busy. Your art is already impeccable and pro quality, just treat the MLP fandom as if it was a new franchise-specific client - try to avoid working on spec as much as you can (or only do it to flesh out your portfolio for the franchise - where you decide what you create and what you share as a part of your portfolio) and then “the magic happens”.
And if you have other online galleries or portfolios that you want people to be able to find from your profile here, just let us know - we’ll set up User Links which are verified links to your other work just like your DeviantArt link so that folks can find your other profiles or offerings.
But that’s just me. You can see from my gallery here that I’m just a dabbler in this franchise :)