I use HO scale sheep for "Shaken", pigs for "Disordered" and chickens for "Routing".
A fellow I know used brigade officers on different coloured horses to indicate their brigades' orders, e.g., a white horse for "Attack", a brown horse for "Defend" etc.
Another fellow kept track of the casualties on his 30YW units with standard bearers. The standards they carried had one through five devices on their flags to represent each hit. He also tracked ammunition with powder barrels in a cart. A particular roll would cause you to lose an ammunition marker and when you were out of markers you were low on ammunition.
Years ago I played in a Johnny Reb campaign in which each brigade needed an ammunition wagon. I've often considered using the HaT French wagons for this purpose.
I've gathered up all my dead horses from Airfix and other sets, painted them and mounted on poker chips. They are casualty markers for cavalry units. I've done the same thing with the various Airfix infantry casualties from their Waterloo series.