Study the ordinary setting
Describe the room, street, or landscape before naming the threat. A believable environment gives a strange detail something to disturb. Notice how light and perspective establish that baseline.
Follow the reveal
In a sequence, mark where the reader first notices danger and where it becomes explicit. Panel size and pauses can stretch the interval. Compare a gradual reveal with an immediate full view.
Evaluate lettering
Letterforms, captions, and sound effects can intensify or interrupt the atmosphere. Ask whether their scale supports the image's focus or competes with it.