I've always put them in a zip lock freezer bag with enough water to cover the fillets. I will then squeeze out all of the air, seal the bag and lay flat in the freezer. Squeezing out the air and laying them flat in the freezer helps eliminate freezer burn by keeping the fillets under the water plus it makes it easier to stack and store the fish. I've had no issues freezing them like this and they will last over a year.Thumbs Up