Most of the advice you read on the next relates to older NiMh batteries. Lithium ion batteries in the iPhone are different.
You don't need to run them down EVERYTIME. Just once a month.
12 hour first charge is bullspit. When the battery is full the iphone stops taking a charge for a bit, then takes a little, then stops, then takes a little. So when it's full, leaving it in for 12 hours will do nothing. No damage, no benefit.
People will tell you not to run it to zero as it damages the battery. If you could go to true zero that would be true but the iPhone won't let you. When it says zero on the screen it actually still has some charge.
The moral to this story? Just use your phone and give the battery no thought. Let the iphone take care of things and you just use it and have fun.