Here is a list of some of the main things that lead to suspense.
1 Start by plunging your protagonist into life-or-death trouble on the first page of your story. Work all other information into the action. You don’t need to spend any time setting the stage. Readers are smart. They’ll figure it out. This is especially important in your first several books before you’ve developed a reputation for good storytelling.
2 Illuminate your protagonist with telling details that reveal important aspects of the person’s personality and emotions. What the protagonist looks like is not important. How the protagonist feels and reacts to life-or-death trouble is very important, and that is what generates our empathy and worry.
3 Give your evil antagonist a background so terrible that we suspend our disbelief and buy into the evil. And make the bad guy much more powerful than the hero.
4 Allow us to witness the antagonist’s evil or have another character testify to that evil.
5 As your protagonist tries to cope with the terrible trouble, make certain it gets worse, and then worse still.
6 Build to a climactic battle on the antagonist’s turf. Give the bad guy all of the advantages so that it appears obvious that the protagonist doesn’t have a chance.
7 Have the protagonist appear to be losing the climactic battle in every way. Remember that your hero can’t benefit from luck or coincidence. When your protagonist finally wins at the end, he or she does so through grit and perseverance and innovative thinking.
8 Make your wrap up, what writers call the denouement, as short as possible. Leave your readers wanting more.
All of these these techniques will create so much suspense that your reader will stay up late to finish your novel and then will order every other book you have written.
Writers who create dramatic suspense are the most successful of all writers.