The first step is to clear the top soil and any organic matter that you have over the soil. Remove any weed or plants that you have in the area. Use a shovel or backhoe to remove the top soil which encourages organic growth.
Now use a soil compactor to tap down the soil well. Compacted clay makes a strong base for the clay. This step is particularly important if the clay of your driveway is loose. Smooth up all areas and level them. To level down, remove some clay. To level up, use stones to fill gaps. It is better to level up the driveway in a way that the center part is a bit higher than the edges. This way a drainage system will be established and rain water will drain off the sides.
Spread a layer of landscaping fabric over the driveway length. This fabric discourages the growth of sprouts between the gravel of your drive which inhibit its appeal. However, if you have hardy clay which is not very fertile, you can skip this step.
Lay a first base of large stones. These stones can be as large as fist size. Apply the first layer of stones. Top with a layer of sand to fill down the gaps. Water down the sand. Now apply another layer of sand.
Now comes the gravel. The first layer should be of large gravel pieces. The second should be of crushed gravel which will bring fineness to the driveway.