(I used LJ-spoiler coding for this -- you just click to expand it. If you right-click and open in a new window, it won't work.)
I didn't upload a picture of this one in its native habitat, so it can be my example.
Now you try! First one:
(Actually, this one sort of stands out, if you pay attention. In a different environment, it would be invisible.)
Here's another magnet cache – this one was called "a scrambled vow."
Congratulations -- you are now qualified to find caches that stump many newbies :).