For the blade grip, wrap three of your fingers around the handle. Pinch the blade between your thumb and forefinger slightly forward of the bolster (the "shoulder" of the knife between the blade and the handle), which should rest somewhere near the base of your forefinger. Many cooks say that the blade grip gives them the most control.
Another option is the handle grip: Wrap your four fingers around the knife handle and hold your thumb along the other side, parallel to the handle. Inch your hand up as close to the bolster as is comfortable. People with small hands may especially like this grip.
Whichever grip you use, we recommend not extending your forefinger along the top of the blade. This hold may provide a feeling of control, but it will tire your wrist unnecessarily. Also, when using a chef's knife, make sure to keep your arm and wrist straight and relaxed.