You won't go very far as a generalist. It's a dog-eat-dog world out in the writing market, with plenty of competition ready to eat your lunch. To carve a niche for yourself, decide on a topic or area that you will specialize in. Then,
i) Read prodigiously about the topic
ii) Talk to people in the industry
Devour books and magazines, and constantly comb the web for
knowledge. The best specialist writers constantly read about their area
of specialty. As a result, they are well-versed in the language, issues
and events relating to those topics. They are like a sponge, absorbing
knowledge all the time.
But it's not enough to read. You
need to be on the ground. You need to be everywhere, from product
launches to press conferences. You need to invest time talking to
everyone and anyone that matters in that particular industry.
Quite often, specialty writers know their stuff so well that their
industry contacts sometimes turn to them to find out the latest
industry news and gossip. When you've reached that level, you would
have carved a niche for yourself.