In my experience, they can be virtually anywhere on your property. But food plots, thickets and fence crossings seem to be the top spots. Also, if you find one shed make sure you spend a good bit of time in that general area, sometimes the other shed won't be far. And then again, sometimes they won't drop the other one for days or even weeks. You just never know and that's what makes it fun. Traps? Not a fan.
Hunting sheds is like an easter egg hunt for hunters. Finding them is a blast, especially a really good one.
Now, if you want to have A LOT of fun shed hunting do this - Go and get your hands on the biggest shed you can find. Then, head to your best friend's farm when he's not there and plant it. Arrange a shed hunting trip with him and "lead" him in the right direction. Get your iphone out and film his reaction. It's like buying one of those fake lottery tickets. Too much fun!