Your characters, as well as your readers, need to respond to the suspense. They may respond in a predictable way or not. This tension may uncover a flaw in their character. Maybe how they respond to stress is with aggression, anger, a flood of tears, withdrawing and isolating, fight and flight response - there are so many options.
Switching between scenes can evoke tension. Someone is trying to escape, while, at the same time, their captor is is approaching, having purchased rope, tape and knives from the shopping mall. A bit like the movie "Misery". They are getting closer as the escapee makes a final attempt to break the window lock. Think of a long lit fuse running to a keg of gun powder. What is happening? Better hurry. Danger looms.
The appearance of a particular shady or diabolical character at an unexpected time can create a good "Oh no!!" moment. Maybe they will be standing right there at the window as the curtains are pulled back. Although this is more of a fright or shock than suspense as such. The suspense would be in the knowledge that this person is lurking somewhere outside the house while all inside are oblivious. Suspense can be maintained from paragraph to paragraph or chapter to chapter. Running then hiding and waiting - hearing sounds - moving to a safer location - maybe from the frying pan into the fire!
Have fun exploring suspense fiction and developing your own style!