I have mastered the art of catching fish in the florida keys. You need to be "one with the fish". I use two of those hand nets with the white mesh. Put one in the fishes path and with the other go in U movements behind the fish. Make sure you keep the net in front moving as to always block the fishes path. Slowly keep moving the nets together the one in the rear a little faster then the one in front. At the last second when there is only a few inches between nets quickly bring them together and hopefully you have a fish!
With this technique please dont use it around corals as you can harm them and cause infections and so on. Use it around areas where rocks have been placed to keep land from eroding or in sea grass comunities. Also flip over rocks to find smaller urchins, pistol shrimp, brittle stars, even small gobies and blennies. But always flip the rock back over in the same way you found it.
Also please note that in florida waters there are some things wou shouldnt catch for legal issues and for the sake of the fishes well being. For example, it is illegal to collect certian stars, long spiney urchins, lobsters (unless during lobster season with the correct license), groupers, hogfish, types of snappers stone crabs, and blue crabs
Fish and inverts you should avoid for their welbeing would be:
Atlantic Blue Tang- does not do well in captivaty and almost always dies
Parrot fish- Need large swimming spaces and have a strict diet that usually causes them to starv in captivaty
Medusa Worms- get stressed really easily and detach their heads
Pearl fish- live in sea cucumbers and need good water motion so they can get the food they need, tend to starve in captivaty.
Sting rays- they're barbs get stuck in the nets and they get hurt.
Any of the eels in florida- just get too big or shouldnt be collected by thenovice collector.
Horse shoe crabs- get to large