I put the fillets in a bowl of cold water as I clean my fish, rinse under cold water and place in a ziplock freezer bag. Fill the freezer bag with tap water so the fillets are well covered. Next I get all the air out of the bag by zipping the bag almost all the way shut and bringing the opening lower than the water until the air is out and the water starts to trickle out - then quickly zip it the rest of the way closed. Freezing them this way keeps them tasting as close to fresh as frozen fish can for up to 6 months.