I'm a cheap tightwad and that's all I use. Obviously if someone needed to individually number a large amount of chickens zip ties wouldn't serve that purpose but I have no need to do that.
My band code is something like black band/left leg = July hatch from red hen. Black band/right leg = August hatch from brown hen, roost bully gets additional white band on a leg, etc. etc.
I band them as soon as they hatch, sometimes the chicks aren't even dry yet. If I install the band loose...
Above the spur allows them to be more easily seen & free of debris. Also if the band is too tight it will be able slide up the leg as the bird grows instead of cutting into the skin.