Here’s a thing I discovered when writing my first book, A Singular Lady: writing about the gentle progression towards love is really, really boring.
The only way to make a romance novel come alive is to write about everything but the romance. In other words, take two people whose circumstances, situation, personalities, etc., would normally compel them to stay as far away from each other as possible and take them on a journey, a slow, inexorable climb to the inevitable HEA. Make it as hard on them as possible. As my pal William Shakespeare likes to say,

For aught that I could ever read,
Could ever hear by tale or history,
The course of true love never did run smooth.

Bill, you got that right. Make them suffer. Make your characters stare down into the pit of despair that is their future, and pull them back only when it seems their fall is inevitable. That is what makes a compelling romance. The stuff that writers sometimes focus on–the first kiss, the first fondle, in Janet’s case, the first bondage–that is circumstantial. It happens because it has to happen, because circumstances dictate that your characters fall in love even though every single thing in their lives seems to point to the other person as being the worst possible person to fall in love with. It shouldn’t be the focus of the book, it should be an unavoidable event, caused by the characters themselves, not the need for massive boinking. A great romance novel isn’t about the romance, or even lust. It’s about making your characters complete. And with completion comes love.