There are many ways that people can get advice. The most obvious ways for writers to improve are to take lessons in the language they will be writing in and the old fashioned ‘read the greats’.
There are times when constructive criticism is very helpful and there are times when your enemies will only have destructive criticism and jealousy to offer you.
Two main ways to get feedback about your writing for professionals: 1) Submit! When the editors will make changes; when the magazine or newspaper or publisher will buy it/pay for it; then that ‘s good.
Great ways to get feedback for amateurs and some semi-pros: join writer’s groups; take work shops or classes. Peer critique is often part of such arrangements.
General to Specific
There are numerous types of writing and most writers specialize. Many of those who have specialized don’t call themselves writers. Grant writers, for instance, will often just say that they work for whatever organization they work at in some administrative role. Journalists, typically prefer to be called journalists, although they could all call themselves writers and be telling the truth. Staff writers may choose to refer to the publication where they work. Most staff writers wouldn’t ever write “for fun” or “as just a hobby” and those that would might well not tell the truth about that.
Travel writers, book authors, niche novelists, political news, best restaurants, fashion, television, film, all have specialized types of writing. There are people capable or more than one kind of writing, but it is common for those who are most successful in the field to find they were forcibly limited to a small subjection of the writing world in order to find a way to earn a living or to develop a good reputation in the industry.
There are times when you have to meet and greet enough others in the industry to get a deal and other times when you really need to mail something for it to work. In some cases, the right thing to do is apply for a job and become a regularly paid publishing company editor for other authors even if you hardly get anything of your own published. Maybe you will, and maybe it won’t matter anymore.
Sometimes writers are stubborn and fail to change in ways that will cause them to have far greater success and other times people just realize that for them: to change that much would be so bad that they might as well go work in a totally different field if that’s really how it works.
Other writers tolerate a lot of painful constructive criticism and make survivable compromises and learn to be a bit more flexible and they find out that they can get a lot further and are happy with the results even though the reality ends up being unlike their original idea.