1. Wear latex (vinyl, etc.) gloves when working around oil, grease. They dry your skin and the cleaners you use to remove them dry even more.
2. Apply "Atrac-Tain Cream moisturizer" (expensive and found only in pharmacies, but works like nothing else I've tried). Next best: Amlactin lotion(also found in pharmacies)
These are go-to's for nurses/docs who wash their hands many times a day (wife is a nurse).