Each fish has a different "best" method for handling and those methods
vary from person to person.
For myself, small Walleyes, Northern Pike, etc are handled easiest by
sliding my hand up their bodies and resting my fingers behind their
gill plates as they open their gills. This can injure large fish so
then I use one of the gripping fish scales made by Rapala and leave the
fish in the water while unhooking and only lift it for a picture. Make
sure you help support their weight with your off hand so you don't
injure them if you lift them up for a picture.

Just my $.02 worth. Hope it helps.

Gary