Depends how you define "published".
1. post a story online in a public forum. You are now a published author.
2. enter a poem or story competition IF the winners and some runners-up will be published in a printed format. Now you are in print. If you're a winner, this adds to future credentials when approaching a publisher.
3. read, read, read. Practice, practice, practice. If it was easy, everyone would do it.
4. Get a synopsis of your book published in a local or national newspaper. National is better, but harder. i.e. get interviewed as a wannabe author and this is your current project (i.e. create an audience, create demand).
5. If even 3,000 people email Amazon and ask for your book, or to place an advance order, you think amazon isn't going to tap some publisher on the shoulder? Of course they will, Amazon exists to sell books (and stuff).
6. Find a good editor. A good editor can make a good book great, and help you avoid mistakes. I had one author who make 2 key mistakes in his novella. First, he used what he claimed was a UK police slang term. I didn't believe him, so I checked with Scotland Yard, who were very helpful (if curious). My author was wrong, but I had the correct slang now. His other mistake was to have the SAS swoop down and capture the bad guys with no shots fired. I explained why the SAS would NOT be used and he opted to change this to heli-borne armed police. Fine. But lucky I was playing shortstop!
7. get into an anthology. You'll get noticed and any costs will be shared.
8. Be sure the book is everything it can be before you take it to a publisher.
9. Send a synopsis. Some publishers have guidelines on their websites. I'd send a brief CV and a brief statement about why you were inspired to write it. Include a brief (1-2 page) plot outline and maybe 10 pages A4 12 point double space text. Size is not a selling point, quality is.
10. Repaper your spare room with rejection slips so that, when it is published and made into a Hollywood blockbuster you can do interviews in that room with all the jerks who rejected you in the background.
11. Don't wait for your not-hooked publisher to buy lunch if that personal touch will seal the deal. One lunch is worth a book deal!
12. The two most important people in the publisher's office are the receptionist and his/her exective assistant. If you don't win over the receptionist you first call is going nowhere. If you can't win over the EA, you're never going to see the publisher.
Good luck!