Carlos de la Garza shares a stereo widening technique he picked up from producer Joe Chiccarelli, built around two Eventide H910 harmonizers. Send a mono signal to both units, pitch one up 1 cent and the other down 1 cent, pan them hard left and right, and add a touch of feedback. The result is an unusually wide, immersive spread that sits well in a mix without feeling artificial.
Carlos used this approach throughout Paramore's "After Laughter" on vocals, percussion, and drums - often on the majority of songs. It's a simple setup with a dramatic effect, and the 1-cent pitch offset is small enough to stay transparent while still generating serious width.