Creating Suspense

I've learned so much in the past few years about writing suspense. I've learned how to keep the tension high by ending scenes with cliffhangers, questions, and disasters. I've learned to up the pacing by being careful with how much introspection I use and by converting as much narrative into dialogue as possible. One thing I just learned with the book I just turned in, was that there are different types of suspense stories and that some are easier to write than others.

1)there is the hero or heroine as some sort of law enforcement person, whether a small town sheriff as in my Feb 2007 release Double Deception, or a cop, or an FBI agent, or a lawyer, or a private investigator or or a DA, or Firefighter, or EMT etc...you get the idea. By the very nature of their job, suspense is built in and they have the resources to pursue the villians.

2)another type of suspense story can have a reporter, insurance investigator, the body guard or the miliatry character. Again by the nature of the characters career choice you can build a believible suspense story.

3)then there's the type of suspense story where the protaganist is in danger, hiding, running, keeping one step ahead of the bad guy. This element of suspense works well with the other two types because if one character is the hunted, then the other by their skill set can protect and help solve the crime, mystery, bring down the bad guy.

4) but what about the type of suspense story where the two main characters are normal humans with average, everyday lives. This is the trickiest type of story to write and keep suspenseful. I've found in this type of story, there is a risk that the characters are mostly reacting to what's being acted upon them rather than actively pursuing the bad guys/solving the mystery.

How does an Economics College Professor and a cocktail waitress/actress work together to stay alive and bring down the guy? This was the feat I had to accomplish in the book I just turned in. What I did to keep the book suspenseful while keeping the hero/heroine together (to build a romance) was to have several subplots threaded through as well as getting inside the head of the bad guys. My current book will also be one of these types, with an investment broker hero and a woman trying to save her family's flower farm. They must work together (and build a romance) to try solve the mystery of who's sabatoging her flower farm. As I start to write I'm sure I'll add a police officer as a secondary character who can be a resource, but as with any good romance, the hero and heroine must be active together.

Are there other types of suspense stories? What are some ways you've found to up the suspense your writing? As a reader of suspsense what do you like about the suspense genre?
I would love to hear what you think!!