To store fish and seafood, I have one simple rule really which is that, if I am buying frozen, I don’t tamper with the packaging, I simply transfer to my freezer immediately. This is essential to prevent food poisoning. If you had a big shop that included fish and seafood, attend to them first and place in the freezer. If I am buying frozen, I tend to date them so I can cook as soon as possible. Goodness knows how long the fish/seafood has been sitting frozen since it was caught. The longer it is kept frozen, the less the flavour, so cook as soon as you can.
If you are buying fresh, make sure you clean and gut out the fish, or with seafood like crab, prawns, mussels, prawns, you will need to either de-vein, take out any insides, give a good rinse and store in labelled freezer bags.
Another option is to portion the fish in freezer bags, season them, seal the bags and place in the freezer, that way when you need to cook fish, you simply empty the freezer bag into your post of soup and Bob’s your Uncle.