We find the crappie like the native shad more than their city-fied store bought cousins, the toughie or shiner minnows. If they are real thick under your lights I have used a long handled dip net with about a 1 foot diameter mouth. We've also used a cast net to catch them. We catch the most with a cast net but it's a lot more trouble than the dip net, which doesn't get as many. Last week I ordered an umbrella net to try to catch them under the light.
Keeping them alive has been the biggest problem. They seem to die off pretty quickly, even in our aeriated minnow bucket. So I took a 3 gallon paint bucket and drilled lots 1/4 inch holes in it. I tie it off over the side of the boat and keep the shad there. They do seem to survive longer.
We also find that they don't survive as long on the hook either. We've tried hooking in the upper back just behind the dorsal find as well as through the lips or through the eye sockets. If a fish doesn't hit them within a few minutes we pull em up and swap em out.
Follow Me, and I will make you fishers of men...Matt 4:19