I use an 8X8 steel plate suspended from a rebar frame by chains, aim for center of plate. When done I hit the plate with a can of spray paint, toss it in the back of the pickup and it is ready to go next time. The reason I use an 8x8 plate is that I'm 81, when I was younger I used a 6x6 plate. I'm not just trying to hit the plate but see where my group lands on the plate.