Engaging characters are one of the most important elements of good writing. My Thornton Mysteries series is historical, so good research is important. Keep the story at a good pace, short chapters. Write from the heart.
I write at the same time every day. I believe having a routine helps. I make certain I have short but regular breaks to stretch my legs, walk around. It's good to get some fresh air. It's important to take care of yourself. Another thing is, I never sit at stare at my computer screen and not know what to write. If that happens, it's best to get up and away from the computer. Clear the head. The words will then flow.