You know what I like about romance books? Of course, the hot sex, but truthfully, the layers my favorite authors weave into their stories. For romances, there should be two main plots in the book.
One, of course is the mystery of romance. You know, the mystery of how they come to understand they should be together (not just because they are compatible in bed, though that is important as it is in relationship) and how they work out their happy ending. A lot of this is internal conflict because love is emotion. Like duh, right?
Second, what is going on in their lives that pull them together? Or make sure they are at the same place at the same time? It can be a missing child, a failing ranch, a killer on the loose, etc. You get the idea. This is the external conflict.
Then you can layer on more. Maybe the two main characters’ families are mortal enemies (Jake: A Southern Crime Family Novel), or hero has a problem with being touched (Full Heat: A Brothers of Mayhem Novel), or heroine reappears after disappearing years before (Circle of Deception: The Circle series). That’s right. The hero and heroine should never be perfect. One can be a little less perfect than the other, but both should have faults. That makes them so much more interesting.
Just be careful with the layers and plots. As an author, it’s important to keep up with
them. The plots need advancement throughout the book, and certainly need to be solved completely by the end. The layers need to show up along the way too. Usually, those faults need to be improved or a promise of improving. Not all of them, but the major ones. At the end of the book, the characters have to be better for knowing each other.
The only exception to solving a plot or improving a fault or more within a book is when it’s part of a series involving one main character. Such as Sylvia Day’s Crossfire series, Darynda Jones’s Charley Davidson series, Laurell K. Hamilton’s Anita Blake series, etc.
Personally, I’ve quit reading series with a same main character. I get bored, and after awhile, the hero/heroine gets on my nerves. Maybe because they do not seem to grow and learn from their mistakes. Don’t get me wrong. The series above and many others are great series (they wouldn’t be NYT best selling books if they weren’t) but it’s just not my thing, my taste.
My series have a couple threads that run through them to connect, but nothing major. That’s why most can be read as standalones. The Southern Crime Family series is 
currently the only one that will need to be read in order. Only book one (Jake) is out. Book two should be in the summer of 2020. The series is about three brothers and their
journey to find love and the true killer responsible for their father’s death. Each book is about a brother.
Another thing about plots. In my books of 60,000 words or less, I try not to throw in a complicated plot(s). Simple is best. If you didn’t, you would limit the romance in such a small book. And no, geez, that doesn’t mean putting in more sex. Romance is emotion. Getting to know each other’s personality traits, understanding why they do the things they do, often learning to trust each other, they are all part of a romance.
For that matter, I write for entertainment. The only place I teach a person something is through my blog posts here (or the workshops I do on occasion).
Carla Swafford, Author 