Here is a video demonstrating the most basic pinch grip exercises; one hand pinch and two hand pinch (2HP).

1 Hand Pinch
Typically done with blockweights, blobs and olympic plates.

2 Hand Pinch
Typically done with olympic plates or the David Horne pinch apparatus.

Pinch grip can be trained for timed holds or for multiple rep sets. Specific fingers can be trained to target weakness or sport specificity. Training the last two fingers has significant carryover to end range gripper (crush grip strength) closes.

Technique: Plant the thumb and "stretch" the fingers diagonally across the top of the implement. Once secured, the athlete should "push" with their fingers with arms extended and locked and finish by driving with their legs.

Pinch Grip Strength Levels

1HP

Good - 4 dimes / 40 blob / 2x25s
Real Good - 5 dimes / 50 blob / 2 x 35's / 45 blob by the face
Elite - 6 dimes / 50 blob by the face / 2 x 45's / 3 x 25s / 2 x 45s (York) / 50 blob + weight

2HP

Good - 150 lbs
Real Good - 180+
Elite - 200+

Find more grip strength articles at:
http://www.dieselcrew.com/articles.htm