This is something I have lived by most of my life.
Write what you know, research the rest, and if you need help, ask.
It doesn't take much to sit down and write something, anything that travels through your mind. But it does take time to learn, to discover diverse ways to say the same thing one reads in the thousands of novels, and millions of poetry laid out before us. That's where the Internet comes in handy, but even then, not even the Internet can give you what you need.
That's when you start asking questions of your peers, friends, family, and continue reading other well-established authors.
Here are some other simple tips:
Set a set time to write each day, be it five minutes or five hours, and stick to it.
Accept criticism, be it good, bad, or indifferent.
Carry a note pad with you when out and about. Jot down things of interest Consider what you write to be somethings useable for background info for you, be it vegetable, mineral, or human.
Get money out of your head. Write because it pleases you. If you think money first, your writing will be shit. Craft it, think of it as your best friend, or even your most private lover.
Don't settle to write in one genre. Expand yourself. Challenge yourself.
Another phrase I have is "Less is More." Oft times the less you say in writing, the bigger the impact on the reader.
And I, like my favorite author, Stephen King; use less adverbs in your writing. "He closed the door firmly." Firmly doesn't need to be there as he closed the door. Words like firmly, gently, softly in most cases doesn't need to be used. It's known as over emphasizing. "He shook his head" you don't need to follow that with "left to right". Get the idea?
Lastly, always remember why you write. Each writer has their own reason. Perhaps just to release tension, create a personal diary, that all-American great novel, or perhaps because they want to entertain the reader.
Entertain the reader. And that is what we do on Prose.