A good sized crappie depends on where you caught one, or where you live. Here in Wisconsin, a 15 inch Crappie is worthy of the wall. I've heard of bigger, and if it was a kid's first fish, then any size fish is worthy of the wall. The best way to keep a fish in it's best shape is to wrap the fish in a wet towel, and keep it in a freezer bag (in your freezer) until you get it to your taxidermist. Any taxidermist will tell you that the crappie likes to lose it's scales during the skinning process, and you need to give the fish every chance you can to make sure it will remain a pretty trophy. Don't keep it on a stringer with a line through it's gill, and don't keep it in a metal fish basket, otherwise you'll trash the fins and lose scales.