Fresh lobster tails are going to be best, but frozen would work well too. To use frozen lobster tails, fully thaw the tails in the refrigerator before removing the meat from the shells. It is important, for taste and texture, to use high quality lobster. Most importantly, make sure you're buying raw lobster tails, not pre-cooked. Never thaw the lobster tails in water, they will become full of water.