depends on what your looking to catch or whats chasing them, if anything. For fluke, bass, or weakies hook em through the lip and out an eye socket like a minnie. If blues are on em or your getting bit in half all the time, hooking them behind the dorsal can result in more hook ups.
you can lip hook fresh dead, just keep em moving. Fileted mullet strips can also be deadly on weaks and bigger kingfish, croaker, and blues. The standard mullet rig (impale em and put hook on in back) is good for small to mid size blues.