I recently posted a thread about my son having gotten a couple of books accepted for publication.
From my perspective, it seemed a long, drawn out process. He has long been involved in SF and gaming type conventions. I believe some of those conventions have “writers’” elements, and he participated in writers’ groups - where I presume people shared info/strategies.
He got an agent - which seemed a kind of convoluted process. I think he got names of agents from his writers’ groups and conventions. It was just a hit/miss process of contacting agents whose client list seemed to suggest they might be interested in his sort of writing. In the end, it just seemed to have involved a great element of luck - having the correct manuscript/proposal cross the desk of the right agent at the right time.
I had discussed with him self publishing, publishing on-line, etc, and he did not wish to pursue those for various reasons.
So getting an agent was a HUGE first hurdle. Then it was a long process of the agent submitting it to publishers. Again, I think it was just good fortune that the agent submitted it to the correct publisher where it was seen by the correct editor at the correct time. So he had a couple of years of just ongoing disappointment, until out of the blue two publishers were interested. He ended up with a 2-book deal with a major publisher (Titan) and a 5 figure advance. Publication is planned for next July.
We’ll see how it sells. But it really seemed like a matter of just beating his head against a locked door. Then when he got an agent, it opened a crack. And when he got a publisher interested, the door was flung open. I’m not aware of any shortcuts. I think it may have appealed to the publisher that he envisioned a several book series set in his particular universe.
Another thing (which my son disliked) - agents and publishers often asked about his on-line presence. In his opinion, maintaining that kind of a presence was essentially a separate job - and a job he didn’t care for. But as you approach agents, it might help to be able to point to whatever else you’ve done - whether you have a blog/website, presented at conventions, whatever.
Good luck!