The very best lure is exactly what they are feeding on right now. That might be shrimp, mullet, greenies or whatever baitfish is schooling. They go nuts yearly over a worm hatch which takes place in the Keys. They rarely will reject a well put silver dollar sized crab (unless they typically aren't starving). For one reason or another I don't have luck with bigger sized real-time lures, 4 or 5 inches is as big as I get bites on, and these tarpon could be a hundred pounds or more.
There is a popular stating amongst those that fish for tarpon "bow to the king". This originates from the label for tarpon - silver king, and also the requirement to offer slack in the line when they do their unpreventable leaps. When you see him coming out of the water you have to direct the pointer of your rod straight at the fish. Bend over as well as communicate as for you can to reduce the chance of him crashing down on your limited line and destroying it.