Chopsticks work through leverage. The first chopstick is almost stationary, giving your grip strength. The second chopstick is as everyone else says, a lever that permits the pinching of items between the two tips. The following instructions are extremely detailed and dreadfully boring. It is a description of an action I can do without thought. All I can say is that it does get easier, and it does get automatic.
Begin by lightly holding one like a pen in your most dexterous hand. Push the chopstick forward so that the place where your fingertips are holding the chopstick is approximately at the midpoint. About half of the business end of the chopstick will be projecting beyond your finger tips. The reason for holding the chopsticks near the back is that it gives you better leverage and control.
Relax your hand and elongate your grip so that the chopstick rests in the crook of your thumb webbing, and your fingers and thumb are lightly curved. They should be relaxed; with no effort to keep them curved and none to keep them straight.
Your thumb and finger tips should be almost in line, as if you are planning to pinch them shut, but not quite there yet. Now, adjust the chopstick so it rests against the side of the tip of your third (ring) finger instead of your middle finger. You may well have to move your middle finger up and out of the way a bit. Your little finger should offer your ring finger extra support.
Further back, along the length, the chopstick should be resting in the crook of your thumb and palm. The chopstick should be held firmly yet without tension by the inside of your thumb and against the side of your palm (the space between your thumb and the first knuckle of your forefinger). This, combined with bracing the chopstick with your ring fingertip creates 3 point contact which is extremely stable; this is good since this is your stable chopstick. It moves very little, almost not at all. At most, it may roll a little as your grip adjusts, or as you hold it more firmly to grasp heavy or awkward objects.
Practice moving your forefinger and middle finger together, independently of the other fingers holding the chopstick. Notice that in order to maintain the grip on the chopstick, it may roll a little. Again, this is normal and to be expected since your whole hand is connected.
Now, add the second chopstick. While the first chopstick bears all the weight and anchors your grip, this chopstick does all the maneuvering. As Marshdrifter explains, the thumb is your fulcrum, and the point around which the second chopstick will pivot. Holding the first where it is, raise your fore and middle fingers out of the way. Rest the second chopstick against the side of your first knuckle (the finger/palm joint). Pinch the chopstick lightly between your forefinger, thumb tip, and the side of the tip of your middle finger. Note that because your fingers are relaxed, your middle finger tip will probably not line up with your thumb tip. What's important is the grip, not where your fingers are. At this point the second chopstick should be roughly parallel to the first. (Actually, although it is easier when using it, you don't have to use the tip of your forefinger, which is handy if it hurts for some reason, all you need is 3 points of contact)
In order to move the tip of this chopstick up and down, move the fingers holding it up or down. Your middle finger will move more than your forefinger. The back end of the second chopstick will cross in front of the first, it shouldn't get hung up on it at all. The chopstick should also roll more or less at all the points where it is in contact with your hand. You again have 3 point contact with your chopstick, which again gives you stability, control and horizontal support. Practice will permit you to get the tips of the chopsticks meeting firmly without crossing (a common sign of too tense a grip or poor lateral control).
Make sure your chopstick tips are level. This is done by lightly tapping the tips in the bottom of your plate (never your bowl), and loosening your grip so that they can even out. At this point, you can try to pick things up. Keep in mind that the angle at which you hold your hand will influence how well your chopsticks work for a particular item. It's more than just getting the tips to meet. It's also about proper placement of those tips and the item you're trying to pick up. Sides, top and bottom, is it heavy and do you need to put more 'arm' into it? It just takes practice.
This is only a general idea of how it works, there are many fine shades of technique which will evolve as you become more confident. Keep in mind that hands do not all move alike and manual dexterity has a lot to do with how quickly it is learned. The mark of chopsticks excellence is to be able to pick up the most delicate soft tofu without breaking it, cutting it in half, or dropping it.
Also keep in mind, chopstick etiquette. Always make sure there are no food particles sticking to your chopsticks as you reach for another morsel. Don't ''wash'' your chopsticks in the gravy whilst searching for some favored tidbit. Don't dig around in piled meat and vegetables, again searching for some gustatory grail. Basically, remember that they have been in your mouth, and if you are eating family style, that it's most polite to keep your germs as much to yourself as possible.
Ack! I can’t believe I left this out! Please don’t throw down those chopsticks in frustration just yet.
How, you might ask, is one supposed to eat: jook and SOUP!!! without a spoon?
Now, if you have a spoon, feel free to use it. Just don’t feel bound to using it. Especially if you are eating jook and have an array of tasty foods laid out on little plates, as well as the bowl of porridge in your hand. Switching between a spoon for the jook and chopsticks for the other things is far too inconvenient.
OK, have you ever watched a chopstick expert eat rice? You’ll notice that the bowl will be in the left hand (usually), with the thumb hooked over the lip of the bowl and the bottom of the bowl resting on the fingers. This is considered the proper way to hold a bowl in my family, because holding the bottom of the bowl cupped in your palm implies that you are begging for food, like a monk or a beggar. Either connotation is inappropriate. Unless, of course, they are true….
Now, the next thing you’ll notice is that the bowl travels a lot. It’ll head towards dishes so that there’s a shorter distance between that sparerib and the bowl: less chance of dripping. It’ll head towards the mouth when things are a little big and may need biting in half: the better to catch the other half of the item (and extremely common when eating noodles that would otherwise be dangling out of one’s mouth in a most unseemly manner).
The key is, however, that often the bowl is held right to the open mouth, against the lower lip. The rice is actually shoveled into the mouth with the chopsticks, not lifted in discrete bites. The chopsticks are held with the tips slightly apart, about the width of a chopstick, and used in a scooping action against the side of the bowl. Slightly separating the tips gives you a wider pushing surface which is more effective, even if some stuff escapes through the negligibly small gap between the chopsticks. Then, bring the tips completely together if you need to scrape a small amount together in a bowl.
This a particularly easy thing to do with rice, especially how it is eaten in much of Asia, starchy. The rice sticks together, and subsequently none gets left in the bowl. If you’ve been a little liberal with sauces or gravy, it still works until you’ve only a few grains left. Again, for those, close the tips of the chopsticks so they touch, scrape all the rice bits together, and push them directly into your mouth.
Now, what about the complete antithesis of starchy rice: soup? Well, it depends upon the soup. The first thing to remember is that there is no stigma attached to drinking directly from the bowl as you would a mug. This is perfectly normal behavior as long as you don’t spill soup all over yourself while singing drunken sea chanteys.
Keeping this in mind, the general rule is to eat large things out of the soup first with one’s chopsticks, and then drink the broth directly from the bowl. This works for noodle soups, wonton soup, etc. For soups that are exceedingly full of small pieces (egg drop soup, corn soup, hot and sour soup) or jook, drink the soup directly from the bowl. In either case, chopsticks are used to coax last bits out of the bottom of the bowl, or improve ‘flow’ as with thicker soups and congee.
Whew! OK, now go impress the world with your chopstick skills. It’s not so hard, is it?