On the Event Information Docs & Files and Email pages there are "Print Document" and "Send Email" drop-down form fields. Using this you can select which document you want to create or email to send. You can limit which documents or email template options are displayed in this field by using the status filter.

Here is an example: Say you have an event with a status of "Booked". In a vast majority of cases you will not need to send the client emails or create documents that are targeted at prospective customers. You would therefore uncheck the "Booked" option for any templates that are used for prospective customers.

To configure this setting, go here: Setup -> Templates -> Documents -> (click Edit on the document name)

To find the Display Options go to the Visibility Tab and choose your preferences.