You can set up automated booking reminders by email or SMS (for an extra fee) which send a message at a predetermined time (set by you) before the booking, just to remind customers they have made a booking. So that is it fresh in their mind.
In advanced settings, go to booking reminders and select if you wish to 'add an email reminder' or 'add SMS reminder'. You will then be presented with a box to add in your customer message. You then need to set the days you wish for the reminder to be sent before the booking date. Make sure you enable this.
Setting up SMS reminders is the same method. Add in your custom message (112 character limit) and the amount of days in advance you wish this to be sent ahead of the booking date. There is also a preview of how the SMS will appear to the customer.
You can set up multiple reminders to be sent and enable/disable at anytime. This allows you to set up different reminders to enable at seasonal times.