SKINNING A FILLET
Article and photos courtesy of Helen Rennie & www.beyondsalmon.com
You’ll need a sharp boning knife (see the picture below) or a utility
knife that has a flexible blade (no picture since I don’t own one).
Put
your fillet on the cutting board skin side down with the tail end on
the left and the head end on the right (or the other way around if you
are left handed). If you have a small piece of the fillet that is of
equal thickness throughout (like you see in this picture, the
orientation of the piece doesn’t really matter. Make a cut to separate
a small flap of the skin from the fillet in the left corner that's
closest to you (or right corner if you are left handed). 
Grab
onto that flap, and slide your knife between the skin and fillet
pointing the blade of your knife slightly into the board (about a 20
degree angle). This way you'll leave the least amount of fish on the
skin.
Slide the knife all the way under the fillet.
Done!

Skinning
a fish steak, like swordfish, is even easier. Place the steak on the
cutting board, flat side down. Slide a knife between the flesh and the
skin and work your way around the steak.
All the recipes on my
blog specify whether to use fillet with or without the skin. But in
case you are curious, here are some skinning guidelines.
Poaching
does not bring out the best in the skin texture. Traditionally, the
skin is removed before using this cooking technique, but if you don’t
have a boning knife or find the above procedure tricky, the skin will
come right off after the fish is cooked. As they say, there is more
than one way to skin a fish (or is it a cat?)
If you are browning your fish in the skillet, on the grill, or under the broiler,
the skin will turn deliciously crispy, so make sure to keep it on. Some
of the fish with great tasting skin are salmon, arctic char, striped
bass, black bass, Mediterranean bass, sea bream, red snapper, trout,
and bluefish.
An exception to the above rule is dense fish,
like swordfish, tuna, marlin, mahi-mahi, and grouper. Their skin is too
tough and should be removed no matter how you are cooking them.
