That's new.
Maybe
@Lady-Smut can give some input?
For all the hype about how much money someone can make... The truth is that more than 90% of Only Fans models never make more than $150 a month.
The problem with platforms like Only Fans is that their business model is based on the fact that most models will disappear after a few months. They're basically a glorified payment processor and you're expected to do all your own marketing and that's where the hard work starts.
For social media marketing, you're going to need some absurdly high numbers when it comes to followers. You'll need thousands because the majority of people who will follow you will never pay a cent to see your content. Instead they're going to masturbate to what you post on twitter, instagram, fb, etc... Honestly, from my experience, social media is a f**king nightmare of freeloaders and horny men in poor nations.
Lastly about foot fetishes,
It's a problematic niche market. Having been an escort, I found that guys who are into feet tend to have performance problems. Plus, they're also very fickle about what they consider to be "good looking feet." So producing videos (content) for them can be a serious pain in the rump! Getting money out of a foot fetishist is best done by a stripper in a bar because they guy can check out all the girls and then ask the one he likes for a * low pressure * dance.
My best advice is chose a different niche.
Try being a hotwife and then film yourself going to swinger /sex clubs and having sex with overweight losers who call themselves a bull. Or, if you don't want to screw strangers then figure out how to surreptitiously film up a woman's skirt while in public.