That's pretty much the way we label as well. We number each circuit breaker and we provide a card in the door of the DB which states the current and curve of the breaker and exactly what each one is protecting. We keep a pdf copy of every legend card we make so we can easily provide a replacement if the original grows legs. Also we label the individual sockets, isolators and light switches with the number of the circuit breaker that supplies them.

The worst labeling I come across is usually in domestic premises, there seems to be a trend of just calling each circuit breaker either 'plugs' or 'lights' which isn't much use when there's numerous socket and light circuits. Also the adhesive labels should be outlawed, they always come adrift over time. All labeling should be traffolyte in my opinion.