Actually, there are a lot of chopstick rules
Where this matters: China and Japan, especially. Other countries like Korea and Vietnam have some chopstick no-no's but are generally less strict than, say, Japan.
In Japan, don't try to pass someone food directly from your chopsticks to theirs. This innocent-looking practice is part of a funeral ritual, wherein mourners pass the deceased's bones between chopsticks. Similarly, you don't want to place your chopsticks upright in your food, as that's also a gesture meant for the dead (in many parts of Asia).
In China, especially when eating at restaurants with others, you generally use a pair of communal chopsticks for grabbing food from a communal dish. Ask the waitstaff for extra chopsticks if needed. And when grabbing food, don't be choosy; take what's closest to you. Otherwise, it's the equivalent of licking your fingers, then running them over all the bread in the bread basket before grabbing one.
In Korea, it's customary to eat with both a long spoon and chopsticks, but you never hold both the chopsticks and spoon in the same hand. That's rude, plus what do you hope to accomplish, anyway?
In Thailand and the Philippines, don't bother asking for chopsticks. You don't need them.
Finally, pointing with your finger is already considered rude. Using chopsticks looks that much worse.