Essentially: Just show your readers that you care and know what you really want.
Well, I agree that spreading your stories with social media is a good way, but personally, I say: don't do a bland promotion where you just drop a link or write a short blurb. Reach out and build relationships, do collabs in the collaborations, do reviews, and offer whatever you can to the community. Once people know you, they're more likely to check out your work and support you.
Also, be confident that your work will succeed. Don't place all your bets on being popular, but place them in your work, and it will naturally succeed in most cases. This also depends on how you define "Success" as well.
For me, success means finishing my story and opening up Ethra for others.
(Granted, in the beginning, I also wanted many views and subs, and they still help motivate me - anyone would want that right? However it’s not my main goal anymore.)
In other’s cases, it might not be so complex. Like what you mentioned up above, “success” can be the views they get, the subs they have, how much money they make, or how much they enjoy creating, etc.
What I'm saying is that redefining what "success" is before creating your real goal is extremely helpful for focusing your efforts into making it come true.
Also, here's a link to a thread with more practical tips from experienced creators with 500+ subs: