Just be careful... Truthfully I would do your helix instead of your cartilage because if it goes wrong you what's called cauliflower ear and it's very bad. If you pierce your helix it's more safe and it's the same area and looks like your cartilage. I would seriously advise you do that so there's no damage. Plus it much easier to do. Just make sure everything is sterilized before you do anything. Good luck.
:O!lolol sorry. Anyways i recommend you go get it done professionally.(: But if you do it by yourself i would say keep it clean. Rub alcohol on it and having a very very very clean needle. OH and maybe rub ice on it so you cant feel it as bad. ((: