Your biggest enemy is ice crystals. They hold water, and water loves to leak out. If you cook it frozen, the meat gets tough and shrinks. That’s a crime against crustaceans.
The best method? The fridge slow dance. Put the bag in a bowl in your fridge overnight. This is not exciting, but it is correct. Never microwave it to thaw—you will cook the edges into salty boogers.
In a hurry? Submerge the sealed bag in cold tap water. Change the water every thirty minutes. It will thaw in about an hour. Do not use warm water, unless you enjoy food poisoning.