I'm an absolute rank amateur, but have made a go at monetizing my writing.
Started on Patreon, with very little idea of what I was doing. Posted irregularly, had a few dozen subscribers, pulled in something like £25/month.
It took some time, but now it's grown to just under two hundred subscribers, about equally split between free members and paying ones. It pulls down about £130-150 a month, now. Not exactly a living wage, but it helps pay a bill or two. And, to be honest, the money taken in from writing fills me with more joy than the money from my day job. It's concrete evidence that not only does somebody out there enjoy what I'm writing, they're actually willing to pay for it.
I started the Patreon less as a secondary income source, and more as a motivator. I feel terribly guilty, now when I don't post or fulfill the expectations I've set. I want to give subscribers value for money, and so the weekly push to publish keeps me going despite the many distractions of ordinary life.
Things that helped the Patreon to grow:
1. Establishing a regular pattern. I currently write a thousand words/day, and publish twice a week (Monday/Wednesday) for the different tiers, with an weekly update on Friday.
2. Whenever my consistency dips, so does membership.
3. Outside promotion! The single biggest thing that helped my Patreon grow was some help from another creative. An artist called Fraylim liked my story and gifted me a bunch of fanart. People seem to like visuals. They also dropped my name on D.A. and membership surged.
4. Publishing across a range of sites seems to have helped as well, drawing in a more diverse audience.
Things I think would help my Patreon grow more:
1. Relentless self-promotion. But I'm terrible at it, and don't think I've got the time for it.
2. Writing shorter, more digestible fiction.