Check with the manufacturer of the glove to determine what type of conditioner is best to use with that particular brand. Softball gloves are made from a large variety of leathers which may respond differently to the various conditioners.
Purchase an appropriate softball glove conditioner. The conditioners can be purchased as a spray, an oil or a cream and are available at most sporting goods stores.
Apply a small amount of the conditioner to the pocket of the glove. Work the conditioner into the glove by massaging the leather.
Wipe excess conditioner from the glove using a soft cloth. Excess conditioner is not beneficial to the glove since it will "suffocate" the material and cause the glove to become heavy. Applying too much conditioner can actually cause damage to the glove.
Apply conditioner to the rest of the glove and work into the leather.
Remove excess conditioner from the glove with a soft cloth.
Form the pocket of the glove by placing a softball in the glove and wrapping the glove tightly with a string to secure the ball in place. The softball should be fit so that it is in the optimal fielding spot in the webbing of the glove. Allow the glove to sit overnight.
Remove the string and softball from the glove. The glove is now conditioned and ready for use.