Del Brown spent many years fishing 200 days a year chasing Permit with some of the best guides in the world, I would say that he caught over 500, (he said) by mostly being persistant.
I've hooked quite a few permit in Southern Belize and it still ain't easy to land them even tho they are usually pretty small.
As far as the Keys fishing goes, for Permit and Bonefish, those are BIG FISH and like all big fish they are tough. So often I hear people try to compare the schoolie fish of Mexico, Belize or the Bahamas to the Keys, but there just is no comparison, big fish are just a whole different world.
I would say for successful fishing there really arn't many secrets you just have to put in a lot of time doing it. And for those of us that prefere big fish; British Columbia Steelhead, Homosassa Tarpon, Keys Bonefish and Permit, you gotta put in alot of time to land a few.