1. Read ALL of that publisher's guidelines.
2. Make sure you POV (point of view) is one character per chapter and not more than three POV's in a story.
3. If you are submitting to a publisher that sells erotic books, PLEASE put sex scenes in the book!
4. Try to have someone non-biased or someone who has been in the business a while look over your manuscript.
5. Submit and then practice patience. Your's in not the only story being reviewed.
6. Do not, and I repeat DO NOT shop your book!!! Nothing is more irritating than offering a contract only to find out you were hedging your bets. It's also a good way to get yourself an automatic no the next time you submit. Also keep in mind, word gets around about that kind of behavior.
On that note, I do hope that everyone is having a wonderful holiday season! Happy Hanukka. Happy Yule. Merry Christmas and Happy Kwanza!