Mine are still young so their combs all look the same. I am attempting to tell by feathers but sometimes that is hard. I have 3 that look different so they are obvious and my 6 rockers pretty much look the same. They are hard to tell apart.I don't need anything to tell mine apart. The rest of my family just calls them "the yellow ones" or "the fluffy one" haha! I'm able to tell mine apart by comb size, personality, and usually some kind of difference in there feather pattern. Oddly, if you spend enough time with them you'll eventually start to see a difference.
I have no experience with leg bands though.