Tap on the Contacts icon on your iPhone, iPad, or iPod touch, and tap into the contact you want to add a phonetic spelling to.
Tap on the Edit button in the upper right hand corner, and then scroll to the very bottom of the contact info.
Tap Add Field, then choose Phonetic First Name or Phonetic Last Name. Fill in the field with a phonetic spelling of the name you want Siri to pronounce.
It seemed too good to be true. And so far, it is.
In testing this tip for myself, I've found that it doesn't actually change the way Siri pronounces the name, just the way she understands it. So if Siri can't quite master your friend Siobhan's name (pronounced Shi-von), adding the phonetic spelling into her contact information will help Siri track down the right person when you pronounce it correctly. Asking Siri to "Text Shi-von" will get you to the right person, but she'll still reply back, "What do you want to say to See-oh-ban?"
It's still a great tip, but there has to be something more to this newly-discovered Phonetic Name field. In practice, it doesn't do anything any differently than the similar Nickname field in the Contacts app. Maybe the directions from Cult of Mac above aren't quite complete? Maybe there's an extra step to ensure that Siri both hears and speaks names correctly?
If you've figured out how to master Siri, leave a comment and tell us how! Everyone with an unusual name is counting on you!