The Dragonet is a very common fish, but we don't tend to bump into them all that often - why? Look at that silly, little mouth. Cute, yes, but you increase your chances of snagging one by reducing your hook size when targeting them. I was using the equivalent of a size 16 here.
Location-wise, look for sand. Can be extremely shallow as they are masters of disguise, but can often be found in deeper water too. I think us LRF anglers are much more confident when we can see a Dragonet. Also, I feel like the pattern in my Dragonet captures is the edge of sand against rock or man-made structure. This one didn't bite until my weight hit the rock.