To succeed at any profession, you must establish goals — both for the longterm and the short-term. Writing is no different. Since authors only improve their craft and hone their skills by writing on a consistent basis, you will need to make a writing commitment.
Some authors find that they are most prolific in the morning. Others become creative late at night. The best way to find out which time of day works best for you and your creative muse is to experiment. Take a week and try writing first thing in the morning, then try writing later in the evening for another week. Naturally, you may have to factor in the obligations and responsibilities of family and work. As a result, you could find yourself having to write at a time of day when you're not at your best creatively. Fortunately, it's not the time of day that matters as much as the commitment to set aside a block of uninterrupted writing time on a regular basis, and stick to it.
Set realistic writing goals. Just as a new runner can't compete with an Olympic-caliber athlete in a track meet, a new writer can't produce the same number of quality pages each day, every day, as an experienced author can. Start with an achievable goal, such as writing one hour a day, and build upon it.
New writers often have no idea what a reasonable daily output for them will be. In fact, it's rare that an author, even a seasoned professional, will write the same number of pages each day. That's because writing is a cumulative process. The work you do today may not be measured in actual pages completed today. You could just be laying the foundation for the pages you will complete tomorrow.
Some writers perform better when their daily writing goal is measured in time, rather than in actual pages produced. If your commitment to your romance novel is to write for one hour each day, and you achieve that goal each day, you have succeeded — regardless of the number of pages actually completed.
Rather than setting a goal based upon daily totals, set a goal for a weekly total. For example, if your goal is to write one page a day, change the goal to writing seven pages a week. This produces the same number of pages each week, but allows your creative muse to operate under its own time schedule.