(Do not be impressed by Georgia. She's been lapped several times LOL. Have I mentioned she's two? :p)
All I did was print out a list with each of my children's names, mat it, and put it into a picture frame. I made little flower rosettes to make it prettier! The way it works is super easy. When you catch your child making good choices, showing a selfless attitude, going out of their way to help another, making sacrifices for others, etc you give that child a mark because you caught them being good! Use a dry erase marker on the glass makes it super easy to wipe away. When you need to add another child, just print a new sheet and put it back into the frame.
I always make a big deal in front of everyone when I give any child a mark. Asking for a mark means no mark for sure! For the bigger kids the prize is ten marks equal a buck. In our allowance-free house one buck for just putting others first is a big deal! For the little kids they get a small treat like a piece of gum or mini candy bar immediately when they earn a mark.