One-Handed Grip
The basis of a two-handed grip is a proper one-handed grip with your non-firing hand supporting your firing hand. To properly hold your handgun with your firing hand, form a "V" with your thumb and trigger finger, and place the pistol's grip centrally between the two fingers. Wrap your bottom three fingers around the grip with all three fingers applying equal pressure; your thumb should rest on the other side of the weapon, but should not be applying pressure. When you're ready to fire, place the first section of your trigger finger (between the tip and the first joint) on the trigger. Your trigger finger should only be used for pulling the trigger, not for holding the pistol.
Fist Grip
The fist grip entails placing your non-firing hand over your firing hand, with your index finger positioned between the middle finger of your firing hand and the trigger guard. Place the thumb of your non-firing hand alongside the thumb of your shooting hand. The fist grip can be modified depending on your weapon. Many modern pistols have a finger support built into the front of the trigger guard; on these pistols you may choose to place your index finger along the front of the trigger guard rather than underneath it. Both techniques are acceptable and you should choose the one more comfortable for you.
Weaver Grip
The Weaver grip is a variation of the fist grip and is preferred by many shooters. To properly use a Weaver grip, wrap your non-firing hand around your firing hand exactly as you would with the fist grip; however, with the Weaver grip, place the thumb of your non-shooting hand over the thumb of your shooting hand.
Palm-Supported Grip
The palm supported grip, also referred to as a cup and saucer grip, provides support underneath your shooting hand. Position your non-firing under your shooting hand with your fingers wrapped around the back of your firing hand. The thumb of your non-firing hand should be supporting the fingers of your firing hand.