Lucky you — it's time for an iPhone upgrade! Ahead of the iPhone 6's announcement on Sept. 9 , it's time to start planning how you'll sell or trade in your old iDevice. There are the old standbys — Craigslist, eBay, and Gazelle  — along with a new trade-in plan  from Apple itself that offers a gift card for use at Apple stores or online after evaluation of the older model.
Ensure you'll get the best value in your transaction — and keep old personal data confidential — by adding the following five tips to your resale to-do list. Your sparkly new iPhone 5S or candy-colored iPhone 5C  will thank you.
- Back up data and do a clean sweep — First thing's first — connect the iPhone to iTunes and back up all of its data. You'll be able to sync it with your new iPhone after you bring it home. And just like a computer, before you sell your old phone, wipe it clean of any sensitive information, apps, and contact lists. Erasing all of your content and settings (go to Settings > General > Reset > Erase All Content and Settings) is great, but go ahead and perform a full restore  in iTunes as well.
- Polish the exterior — Cleaning your old iPhone is kind of like cleaning your LCD monitor — you don't want to use any harsh chemicals or, even more damaging, water. Using a tried-and-tested cleaner like iKlear ($30) will ensure you won't damage its sensitive bits. Use a microfiber cloth to shine that baby up.
- Take eye-catching photos — No one is going to buy a used iPhone that looks terrible in pictures when there are plenty of glamour pics online of used gadgets. Ensure your ad is pushed to the top of someone's wish list by using our tips on taking great resale photos . This is also a good time to play with your camera's macro settings for clear, crisp, up close, and detailed shots. If you have the original box or accessories, be sure to include those in the photos as well.
- Scope out the competition — Take a gander at other iPhones on sale at various reseller websites so you know the kinds of prices people are expecting.
- Be honest — When creating your ad, be sure to list any scratches, dings, and problems you've encountered with the phone (like persistent low battery life). Being upfront and honest is the easiest way to make a solid sale — people like knowing what they're getting into.