But - here is another secret: Your freezer is part of the problem - if you are using a self-defrosting freezer. The better type for longest storage is a commercial type. Which simply means that it is not an auto defrosting unit.
In the auto defrost mode - the freezer must warm up to (usually) the lower 40'sF - long enough for most of the ice to melt, and drip down to the pan below your freezer. During this warming period - everything in the freezer is also beginning to defrost on the edges. So - when it re-freezes, you get the little ice crystals forming on your food that we all call - freezer burn....
Now that there is some good info!
I guess I never really thought about what causes freezer burn.