Start by clipping the neck, or stems, with sharp scissors or clippers, keeping 1/2 + inch of of neck on the garlic. This remaining stem will allow the bulb wrapper to stay in place during storage. If necks are cut to short, the top of the cloves will be exposed to air, which may reduce the storage life.
Next trim the roots, leaving about 1/4 to 1/2 inch intact. Remove any
dried dirt that remains on the roots by gently rubbing the base of the bulb. Many people remove the entire root (which is the European standard), both will store fine as long as the cloves are not exposed to the outside environment.
Finally remove any dirt remaining on the bulb. The idea is to keep as many outside wrappers on the garlic bulb as possible - for longer storage. However, the easiest way to remove dirt is to remove the outside wrapper where the soil actually laid next to the bulb. When the garlic is properly cured, it should be a quick and easy passing of the hand to remove a single layer of wrapper, exposing a clean and unbroken garlic bulb. Applying to much pressure may remove more wrappers, and sometimes 2 layers may need to be removed to clean all the dirt from the bulb. If dirt remains near the bottom of the bulb, near the roots, use a tooth brush to softly scrub the dirt away.
When cleaning garlic, give each bulb a light squeeze. If the bulb feels soft or damaged try to pull it aside for first use. If the bulb is soft, damaged, or bruised it should not be added to your long term storage. Many times, a soft bulb will have 1 damaged clove which can be removed, while the rest of the bulb could be used before the rest of your stored garlic.
A mesh net bag, in a cool room, with plenty of airflow, is best for long term storage. You can use an empty orange, potato, or onion bag that can easily hang. keep out of direct sunlight, and avoid hot spaces for best long term storage.