A. The first would be to do some serious marketing research. Use the Christian Writers Market Guide to identify several potential markets for what you write; read the market guide listing for each one; copy their guidelines from their Website (or send for them); read them, using two colors of highlighters—one for statements that indicate the market is right for you, the other for statements that would disqualify your writing. If magazines, get sample copies and read them cover to cover, making notes on anything you discover. Then start submitting regularly to each magazine you determine is a fit.
For book publishers, copy the guidelines from their Website (study carefully) and order a copy of their catalog, if available. Check catalog to be sure they don't already have a book on your topic. Buy (or borrow) and read two or three books from publishers you are interested in submitting to. Prepare your book proposal exactly as they indicate in their guidelines.
The second tip would be to attend a writers' conference—at least once a year, if possible. If you are a beginning writer, you can learn more about the publishing business in those few days at a conference then you will by reading a lot of books. You will also start making those important connections with agents, editors, and other writers—plus learn so much about your area of writing from the workshops you attend. If you are more experienced, those connections to potential agents or editors will be critical to your success. Editors are much more likely to buy from writers they have met than from complete strangers. Take every opportunity to speak with editors about your writing projects. Chances are they will not buy your book on the spot, but you will be laying a foundation for future sales. Just be sure to select a conference that will best meet your needs at the moment. Some conferences offer only instruction (great for beginning writers), while others have either a limited number of agents or editors in attendance—or a large number of them. Choose wisely.
My third tip is to write! And to write a lot. All the marketing savvy or conferences attended make little difference if your writing is not good. It's easy to fall into the trap of spending too much of your time talking about writing, attending conferences or writers' groups, immersing yourself in social media, and anything else that keeps you from the computer. Time spent writing should come before any other writing-related activities. Never wait for the best time to write—or until you can get away for uninterrupted time. A writer writes—no matter what the situation.