I've found that while great to look at, the iPhone can get scratched up pretty easily. To avoid this, it's natural to buy a case and/or screen protector. However, by buying the wrong case, the back of your iPhone can easily get scratched! Here's a few little tricks that I used when I purchased my awesome case.
It's always helpful when someone who has mistakenly bought an item can pop out of the random blue to stop you from purchasing an item that will soon be a waste of money! So read up on comments left by customers that previously purchased that item by shopping online!
If you're purchasing online, after having found the item, check and see if they have it at an affordable price on eBay. My boyfriend found an exact same item sold on apple.com on eBay for $10 cheaper.
If you prefer to actually see the item, I suggest that well, first you look up the item of choice online and then checking the store near you to see if they carry it.
Did you know that there's a clear shield for iPhones? If you'd like something other than a bulky shield -although I don't find mine bulky- head to your local mall to see if they have a kiosk that provides the stick-on shield, or you can check out their website on http://www.Zagg.com.
I found that silicone cases prevent scratches more so than the hard cases. Have you ever seen the cases with a circle cut out to show the apple on the back? Don't. Those will let in little dusts and who knows what from your pockets and/or bags that scratches the back of your iPhone.
Make sure that your case is snug and be sure to clean it out once a week. Just because it has a case on doesn't mean that it's fully protected. Once dusts or even little grains of sand gets into it, the tiny movements of the iPhone from little bumps will scratch your phone.