How can I sharpen my canines without damaging them?
In the best simplest less expensive way... please. Thank you.

Why do you want to sharpen them? We've had other people ask the same question, and they are going for the "vampire-look". If that's the case for you, consider going to a costume shop and buying a set of fake vampire teeth. I'm not talking about the crappy plastic ones; a good shop will have two loose "teeth" which you apply to your existing teeth with a bonding agent. They look very, very real. Best of all, they are removable so if you change your mind in the future, you aren't stuck. They won't be terribly expensive. You might also be able to find a dentist or orthodontist who will make you fake teeth to bond to your natural teeth, and possibly a retainer with "flippers" to get the look you desire. With the option of the teeth you attach, remember you are risking damage to your enamel depending on the type of bonding agent used, as well as damage to your teeth during attachment/removal.

Good answer

I am thinking about doing this to, but not fully convinced though.
You can achieve it by using a Diamond coated nail file which you can purchase at any drug store. You can also use an over the counter product called "Ora-Jel" to help reduce any pain level attendant with the filing down of the teeth.
Good luck :)