Refinishing cabinets is a large undertaking, and it is imperative that you follow these steps to get a grade A product. First is preparation, the surfaces must be CLEAN and sanded. The amount of prep will be determined by the amount of filth that has accumulated on the cabinets, and the type of finish. When cleaning, I like to use a non-rinse TSP substitute and a green scrubby. After the surfaces are free of contaminates, you should sand the entire surface. I always sand enough to dull the gloss of the previous coating to ensure proper adhesion of the top coat or primer. The amount of sanding involved, will depend on how smooth you would like the surfaces, and what type of product that will be applied. A good example: if you are going from a lacquer system to a waterborne system then, you need to really rough up the surfaces to be painted. From this point you need to decide what product that you are going to use, because this will determine if you need a primer and what type of primer it will be. If you have decided to paint, then you must use a primer that is going to stick to lacquer, varnish, or urethane. I use white shellac, or quick dry oil base primer, or last resort a waterborne primer not waterbased. I will only use waterborne primer if fumes are an issue. When choosing a waterborne primer it is very important to choose the right product, because if you don’t choose one with tenacious adhesion you will be sorry! Always apply two coats of paint, preferably something that cures fast and is non-blocking. This will prevent the surfaces from sticking together and it will be easier to clean. If you are planning to use lacquer, urethane, or varnish, then you should apply the appropriate sanding sealer before application of the top coat. In some cases this will act as a bonding agent. It is also easier to sand the sealer than the finish. If you do it right, there will be very minimal sanding before the last coat is applied. It is always a good idea to do a little investigation on the products before you apply them, NOT ALL products are created equal.