My best advice is to start simple with suspense. The biggest mistake I see is when a writer throws in everything but the kitchen sink to their romantic suspense novel. The heroine discovers she’s pregnant, by the cowboy down the street who has amnesia and can’t remember that he’s the father of another baby on his doorstep left by his ex who just died in a car crash but he never forgot the heroine.
Think of your plot as a growing circle and not a line that keeps getting longer. For suspense, you need to build momentum. It’s much easier to think in a line. This happens, then that. A linear plot is not so compelling for the suspense reader. We expect the excitement to build, growing in layer to that big, unforgettable ending. Instead, you might see something like this: The heroine falls down the stairs. She dusts herself off and then gets mugged. After that, she gets hit by a car. The hero comes along and then they both get kidnapped. Long story long, too much happens. It’s not how much you put in the story, but how you tell it. For a suspenseful romance novel, you don’t need a lot of ado to get to I Do.