Immerse yourself in the language, lifestyles and relationships of the Regency period by renting DVDs such as "Pride and Prejudice," "Emma," "Cranford," "Sense and Sensibility," "Mansfield Park" and "Persuasion."
Pay particular attention to the strict rules of courtship that were observed (i.e., unmarried couples could not meet without a guardian present), the interactions between upper-crust families versus the laboring classes, the formal dialogue, the music and how individuals conducted themselves outside the privacy of their own homes (i.e., males had much more freedom than females).
Read and study the works of classic Regency authors such as Jane Austen and Georgette Heyer, as well as contemporary writers who were inspired by their stories. Regency novels adhere to a strict set of rules in terms of their structure, social conflicts and point of view. Common themes you'll find in these stories relate to arranged marriages, false engagements, matchmaking for friends, fancy dress balls, carriage ridges and subplots involving the romantic interests of secondary characters (usually the heroine's best friend or sister). As for intimate relations, a chaste kiss on the back of the hand or the cheek was permissible only if a promise of marriage had been made and was blessed by the heroine's family. See the links in Resources for additional information about Regency etiquette, economics, arts, fine dining and entertainment.
Make note of the publishers in the Regency novels you are studying for background. The majority of these have listings in "Writer's Market" (an annual resource published by Writer's Digest Books) as well as websites that provide their complete submission information. If you haven't started writing your Regency novel yet, take a look at these guidelines, especially insofar as desired manuscript lengths and whether you need to submit queries and partials through an agent. For the publishers who do require agented submissions, you can find a listing of prospective reps at AgentQuery.com (see link in Resources).
Outline the Regency novel you plan to write. The first consideration is to identify your female and male leads who, by the end of the story, will become blissfully engaged. Identify the obstacles that will keep them apart for the bulk of the story. These could include such things as respective families not liking each other, the heroine's obligations to take care of an infirm relative or misunderstandings on the part of the heroine and hero that there are other suitors in the wings. Determine the "voice" of the story. While a first person narrative by the heroine communicates the intimacy of a diary, keep in mind that it may limit you in terms of getting inside the heads of other characters or showing what they're doing whenever they're out of your heroine's line of sight.
Structure your outline into three acts. The easiest way to do this is to decide how many total words your novel is going to be and divide it by three. By the end of the first act, you'll need to introduce a major turning point that threatens to keep the couple from getting together. For example, suppose the heroine's least favorite but extremely pretty cousin shows up for a month's stay in the country and immediately sets her sights on the dashing hero. Even if the heroine herself hasn't been paying that much attention to him or regards him as just a childhood friend, she'll be plunged into the panic of possibly losing him. By the end of the second act, you'll need to introduce an even bigger problem that complicates the equation, raises the stakes and forces the heroine to take risks. Example: The heroine has been asked to accompany her elderly aunt to London for 2 weeks. Her fears about "out of sight, out of mind" radically escalate but there is no way she can wriggle out of this new obligation to her own family. She concocts a plan to make him think he has a secret admirer in the country so that he'll be distracted for 2 weeks trying to figure out who it is; maybe she even enlists the aid of a friend to have anonymous notes and little presents delivered to him. Although everything will be resolved by the closing chapter, you still need to keep your readers guessing up until the end. Will the hero's heart stray to the cousin while the heroine is away in the city? Or will it turn out that the cousin was only using him to stir the jealousy of his older, bachelor brother? In the spirit of traditional Regency romances, of course, the hero was never interested in the cousin at all and may even have figured out the amusing charade on his own, a discovery that makes him appreciate his lady fair's imagination even more.
Join organizations such as Romance Writers of America (rwanational.org). This is a place to network with fellow romance authors as well as read interviews and articles on the craft of romance writing.
Recruit your friends to read your Regency dialogue out loud for you. This will help ensure you haven't planted modern colloquialisms, slang or references to global warming into your 19th-century conversations.
Start or join an existing romance writers' critique group. Writing is a solitary craft and the encouragement and support of fellow writers who are interested in what you're doing will help light a fire under you. At a minimum, you need to tell your family, friends and associates that you're writing a Regency novel and enlist their aid in asking you every week, "How's the book coming along?"