Rubs can be used in two ways, wet and dry. A dry rub is made of herbs and spices and can be rubbed into fish, veggies or meat. Wet rubs are a blend of spices and seasonings with the addition of a liquid, to form a paste, typically using oil, honey, liquor, citrus juice, mustard or a sauce. Combined with spices, a wet rub is perfect for cooking food on a lower heat for a longer period of time. Beyond this, practically anything goes. What you want to use for your rub is really a matter of personal taste. A good rub will enhance flavor & color but won't overpower the flavor of the meats.