· Already be following your airline on Twitter
If you're on Twitter and you've handed your money (and your life, incidentally) over to an airline, you should at least follow them for weather and operational updates. If an airline replies to your inquiry, it's best that they do it via DM, or Direct Message, to keep your travel details as private as possible. In order for them to DM you, however, you've got to follow them so they can follow you.
· Give as much information as possible in your first tweet
Speed up the process for everyone involved by being completely clear and specific. A good public intro tweet to your situation is: "HELP: Need rebooking between XXX and XXX. Please advise." Once direct messaging, always provide your airline confirmation code, your departure and destination airports and any preferences (like first flight available, non-stops only, will consider connections or even specific flight numbers if you know what you want to try for) and your full or last name.
· Be short and specific
This goes back to the previous tweet a bit, but refines what you should say. Use as much airline talk as you are comfortable with, like airport codes, which are also helpful as tweets max out at 140 characters. Avoid texting slang as much as possible, because illegibility could get your tweet passed over. Here's a sample of a great starter direct message: "@Airline Hi! Please help me rebook to first available flight LAS-JFK. Confirm code XXXXX. Prefer nonstop."
· Be appreciative and positive in tone
Everyone has somewhere important to be and it's nice to remember that the airline staff helping you are doing the important job of shuffling around thousands of travelers between hundreds of airplanes and airports, around dangerous weather conditions. Be nice. Be positive. Be thankful for help given. You don't know, but perhaps your reasonable tone will help the airline employee tweeting with you to relax a bit, find the flights you need, and take confusion and frustration out of the picture. The weather is not an airline's fault. If they succeed in rebooking you, a good thanks tweeteither at them or for all to seewould be something like this: "THANKS! I see the new confirmation emails/details and I appreciate your excellent help very much."
· Continue to monitor the situation
Just because you're rebooked doesn't mean that that flight won't also be cancelled. During major weather events or airline strikes, following @BreakingNews and another news outlet like @CNN can alert you to airport closures. Check your flight status periodically on a tracker like FlightStats.com or an app, and keep your confirmation code handy always.
A bonus tip would be to make sure that you've already joined Twitter and are at least somewhat familiar with it. There is nothing worse than attempting to teach an exasperated friend traveler about Twitter over the phone so they can also benefit from rebooking this way; if they were already on Twitter, everybody would be having a smoother day.