Apply drywall tape to the joints between the sheets. The tape should be straight and should overlap both adjoining sheets evenly.
Cover the tape with a thin layer of drywall mud. Use just enough to completely hide the tape. Use a putty knife to smooth the mud into a uniform layer.
Cover the wet mud with drywall paper. Run a putty knife across the paper to force out any bulges or air bubbles.
Apply a second coat of drywall mud on top of the paper, smoothing it into a thin, uniform layer using a 12-inch finishing knife.
Feather the drywall mud using a damp drywall sponge. The mud should merge seamlessly with the surrounding sheetrock. Allow the mud to dry for 12 hours.