Cover your floors with drop cloths to protect them.
Fill a bucket halfway to the top with drywall mud.
Add several cups of water to the bucket to thin the mud.
Attach a ribbon mixer to an electric drill.
Mix the water into the drywall mud with the ribbon mixer.
Check the consistency of the mud. It should have the texture and thickness of a milkshake. If it does not, add more water or more mud until it does, mixing thoroughly each time.
Pour the thinned drywall mud into a paint tray.
Cover a paint roller with the drywall mud.
Roll the mud over the wall. The fibers of the paint roller will leave behind peaks and crevices in the drywall. If you roll the roller quickly, the texturing is flatter, while slow rolling creates sharp peaks and valleys.
Continue rolling the mud over the wall until it is entirely covered.
Allow the drywall to dry for 24 hours.