While many people fear sharks and have creepy nightmares featuring these cartilaginous fish, it's actually much more likely you'll die in your bathtub rather than to become a shark's snack.
What the average american considers a "shark" ranges between the tiger shark, bull shark, great white shark and the hammerhead shark, but that's not the end of the story.
There are actually over 400 species of sharks. The smallest ones (dwarf lanternshark) are about the size of a bellow-average manhood, 6.7 inches, while the biggest shark (the whale shark) measures 39 ft, in average... that is... a big manhood.
Even through it is (as stated in the Facts section) quite unlikely that you will ever be attacked by a shark or be killed by one, this statement brings little or no comfort to the person unlucky enough to be that 1 in 3,748,067. There is not much advice you can give to somebody in such a situation (other than "Swim faster!!!"), but what CAN be done is spread the word about some tips that will make it LESS likely that you will fall prey of (ta ta TAAAAAAAAAN) sharks.
1. Sharks haven't learned to fly or walk in dry land, so, if you stay out of the water, you'll be safe. This includes rivers, because bull sharks and river sharks can inhabit both fresh water and seawater.
2. If you MUST get in the water (i.e. you're a surfer, diver, fisherman, wakeboarder, etc.) first of all pay attention to water monitoring agencies. It's easy to know if there's gonna be a horde of hungry sharks waiting for you underneath the waves, just tune in to the right radio station.
3. After you've made sure the cost is quite clear, you might wanna take a look at your gear. Remember the classic all/black wet suit? You might wanna go to the store and get something a bit groovier. If you dress LIKE A SEAL and sharks LOVE EATING SEAL, then you might as well dress Playboy's Miss October in a micro mini skirt and throw her in your local bar populated with sex-starved, middle-aged men. Remember that hot yellow, red and orange are colors associated with poisonous animals, so wear something that screams "You eat me and you'll dieeeeee, hahahahaha!!!".
4. When you see your friends waving desperately at you from the safety of the sand don't just wave back and look cool, they might be telling you to get the hell out of the water. If you are in the presence of a shark, don't splash around idiotically, this might lead the shark into thinking that you're an injured fish. Move smoothly but rapidly towards the shore.
5. This is like Survival 101, but if you get a cut or have an open wound, just get out of the water, sharks can sense particles of blood in the water at impressive distances, so swimming with an open wound is basically a deathwish.