Decide on the type of romance. There are numerous types of romance novels ranging from suspense, historical, inspirational, erotica, or supernatural. Take the time to read up on the different kinds of romance fiction available to help you decide.
Decide on the length. Novellas range from 20,000 words plus and usually in a series of books that have the same characters throughout. Romance Writer's of America explained how novellas tend to be attractive to a publisher because they are sure to gain revenue than taking a chance on a new author for one novel. Plus if you sign a contract for a series you tend to make more money for yourself. A novel is about 65,000 words plus and is a single title, which can stand alone without any relating books. There have been some novels that are written in a series with the same character as well.
Pick your target audience. Decide whether you want to write for YA (young adults) or adult romances. This will help you as far as deciding how you want your characters to talk and behave.
Check out the competition. This will give you a chance to see what publishers are looking for and to learn what kinds of romances are selling.
Begin writing. This is the time to put pen to paper and to begin with an outline. Your outline can help you decide on what characters you are going to build your book upon. Make sure to start the first chapter off with an action. This will draw the reader in and make them want to read more. Decide on a theme, setting, and tone of your romance.