Always look for a salmon that is firm to the touch, but bounces back if you press the flesh. The cut shouldn't have any liquid pooling around it and the meat should also be translucent and moist.
Salmon can be stored in its original packaging for up to two days. For optimal freshness, unwrap the salmon, gently pat it dry, and wrap the filet tightly in plastic wrap. Fish like salmon usually fare best at the bottom of the refrigerator.
It is important to capture as much moisture as possible. Wet the salmon, wrap tightly in plastic wrap, and wrap again with aluminum foil. Place the filets in a freezer bag and keep away from the door to ensure a consistent temperature. If the salmon has been previously frozen, do not re-freeze.
The best way to store fish is over ice. Remove the fish from its original packaging, rinse under cold water, and dry with paper towels. Set fish on a cooling rack and place inside a container filled with crushed ice. The ice should reach just beneath the fish, but shouldn’t touch it. Cover the container, rack, and fish with plastic wrap or aluminum foil and place in the fridge. If the fish is stored longer than 24 hours, be sure to swap out the melted ice with a new batch. Ideally, any fresh fish should not be stored for more than two days.
Some fish can be frozen for up to year (with three months as the standard), but its freshness depends entirely on its exposure to air. To limit this from taking place, you should first clean the fish, wrap it in aluminum foil or freezer paper, and place it in a freezer bag. Press down on the bag before closing to eliminate any excess air.
Thawing frozen fish is quite an easy process. Simply leave it in the refrigerator overnight or place the wrapped fish in a bowl of cold water. Don’t microwave the fish, as some sections will cook while others are continuing to thaw.
Turn the salmon and cook on the flesh side until the salmon is done to your liking (about 1 minute longer for medium-rare). 
Transfer the fish to a warmed serving platter and cover loosely with aluminum foil. Let it rest for 5 minutes before serving with the sauce. 
