I used to release all of them to get bigger except for a few 5# browns to mount. Now the native brookies around me have a problem, they are absolutely delicious compared to the browns. I leave the head and fins on unless they don’t fit in the pan. I love eating the fins like little chips. As far as cooking them, flour salt pepper fried in butter maybe some lemon at the table. My favorite fish to eat hands down. I’d trade ten walleyes for a fresh brookie.