In order to get the best results from a concrete stain, you'll need your driveway surface to be completely clean. Begin by degreasing the driveway's surface using either a retail degreasing solution like VelveTop, available from home improvement or hardware stores, or a solution consisting of Dawn dish detergent and water. Remove as much of the oil from your driveway as possible, and then use a power washer to clean the surface of the driveway. When it's dried, sweep away any debris or dirt, leaving a clean work surface.
Mask the lawn areas next to your driveway using plastic sheeting to protect your lawn from runoff from the stain application. Stains come in an acid-based or acrylic-based mixture. Acid-based stains tend to result in richer colors while acrylic-based stains are easier to work with but appear slightly opaque. If using an acid-based stain wear a respirator. For safety, wear protective clothing when using the stains including rubber gloves, goggles, and boots.
The surface of your driveway should be between 45 and 95 degrees F when applying the stain so the project should ideally be done during the Spring or Fall.
Start applying the concrete stain in the corner of your driveway, spraying a smooth coat. If applying multiple layers, allow each layer to dry between applications. Drying time depends on the stain used, and the driveway should not be walked on until it has dried completely or permanent footsteps will result. Multiple layers tend to give a more complicated look to the stain with more variation in the colors.
You can achieve a textured look to your stain by applying multiple coats selectively, coating some areas more than others. By faux-painting your driveway through the multiple coating applications, you can create a natural look that simulates unpatterned stone.
Allow the last coat of stain 24 hours to completely dry and then apply a layer of sealant using a low nap roller. The sealant may leave your driveway slick when it gets wet so a non-skid or slip-resistant sealant should be applied to prevent falls. If you cannot find a specialized slip-resistant sealant, you can use an additive like Sure-Step that, when combined with a concrete sealant, will provide slip-resistant properties.
Concrete stains will fade with time due to exposure to sunlight, the elements, and ordinary wear and tear. Apply a new coat every few years to freshen up the look of your stained driveway. At most you may be able to go five years between staining, but most driveways will require an additional coat about every three years.