It's important to respond to booking inquiries and reservation requests within 24 hour, in order maintain your response rate. Before you confirm a booking, get to know your prospective guest to see if you're a good fit for one another. If their plans don't match your hosting style or what your listing has to offer, just decline the reservation promptly.
Every time a guest reaches out—whether you have a booking with them or not—it's important that you respond quickly. Timely responses show travelers that you’re an attentive and considerate host, but it's not the only thing that matters. Make sure you maintain a helpful and polite tone, and find opportunities to personalize your communication so that you can build trusting relationships with other members of the Airbnb community.
When you have a confirmed booking that's about to begin, you should communicate with your guest shortly before their arrival. Ensure they know how to reach you, and see if there’s anything you can do to help make their arrival more comfortable.
And of course, if something about your listing has changed since the time you confirmed a booking, communicate it in advance. If your roommate moved out and took all the pots and pans with them, your guest deserves to know.