Airbnb is quite helpful in sending you reminders as a host, for example, they might send you a reminder a few days before the guest arrives, and they'll prompt you to reply to each message in less than 24 hours. But if you want to be a "Superhost", this is not quite enough and you'll want to be a bit more on the ball.
There are lots of different blog posts with examples of what messages can be helpful to send guests. To help me with personalisations I looked at an official Airbnb tips page and Airbnb Message Template Examples. In general, I send about 4 or 5 different messages throughout the whole process…
1. Booking confirmation
2. A couple of days before they arrive to remind them of arrival times and transport directions
3. The morning after the first night to make sure they're comfortable and I'm meeting expectations
4. A day before they check out to remind them of check-out times and the process
Sending messages throughout the process means I need a few more reminders than Airbnb sends me.