Emergency communication (EmComm) is passing information for people who need it when normal systems are down or overloaded. The skill is not fast talking or fancy gear. It is being calm, accurate and predictable, so that the people relying on you can trust what you pass.
Accuracy beats speed
Accuracy first: a slow, correct message beats a fast, wrong one.
A message that is wrong can send help to the wrong place, so the habits are plain:
Listen first. Hear what is already happening before you transmit. You may be about to interrupt something more urgent.
Write it down as it is given, then pass it exactly. Do not tidy it up, summarise it or add your guess.
Read it back to confirm. If a word is unusual, a name or a number, spell it with the phonetic alphabet.
Say plain language: what you mean, in ordinary words, rather than slang or jargon. Other agencies on the same net may not know ham shorthand such as Q-codes.
Stay in your role
Emergency work is organised. Someone is in charge of the net and someone else is in charge of the response; you are one link in it. Do the job you were assigned, take direction from the net control station, and do not self-dispatch (head somewhere because you think you should) unless you are asked to. Responders keep track of who is where, and an unexpected volunteer is a problem to manage.
Information is not yours to release. Details about casualties, damage or response plans belong to the served agency (the fire department, emergency management office or Red Cross chapter you work for). Pass them only to the people you are told to, and leave public statements to whoever speaks for the agency. This is a matter of both privacy and trust: agencies stop using volunteers who gossip.
The rules do not change
No emergency organization or agency suspends Part 97.
FCC Part 97 still applies in an emergency, whether or not you are working with ARES, RACES or a government plan. The rules also forbid anything that hides the meaning of a message, so you do not encrypt traffic. The single narrow exception allows a control operator to go outside their license privileges, but only for the immediate safety of human life or protection of property. See Part 97 in plain words.
In practice
Check in with the net, then keep transmissions short so the channel stays free for urgent traffic.
Be reliable before you are clever: a working, simple station beats a complicated one that fails.
Look after yourself: eat, drink, rest, and hand over to a relief operator rather than make mistakes when tired.