Writers on their own, with a book in hand, may need an agent or representative, because agents are closer to the publishers. Agents are also good because they save the writer having to concentrate on marketing work as well as writing it.
Or one can go it alone in the grand scheme of choices a writer has in getting their work published. Send an email. Try and meet the publisher, even if out of town. This is the hard work of marketing one’s work alone.
Some go out to the workforce and work as a writer, full-time. They are in the job as it was.
For freelancers, if one goes the agent route or the self-motivated route, one should try and make their work their best. Unless your less polished work finds a home, which is always good for the writer. It does happen.
There are cold, hard facts present, but not set in stone. Like book publishers and agents won’t try something unprofessional from a newbie so it pays to do your best.
Magazines and journals can only publish a few of the submissions they receive because of space so it makes sense to only send the magazine your best.
A problem is that one can get desperate and send willy nilly, just trying to get your book out there in the marketplace, and make royalties (sounds good, royalties).
Ideally, one should hone one’s writing, before taking the plunge. Sometimes, one may find out the hard way through rejection of one’s work.
Though, sometimes writing takes off, without one seeing to coming. One gets published although the writing isn’t your best potential, it isn’t as good as it could be.
The reasons for this are probably varied. One reason for this is that the writer has a personal affinity with the publisher’s content and beliefs and the writer writes well enough. The publisher can see the genuine article and that you are on board with them.
Either through acceptance or rejection, keep on writing, for the sake of craft and publication.