Saved Responses can save a lot of time from typing common replies on tickets.
To set up Saved Responses, visit Administration > Saved Responses:
Provide a descriptive name for your saved response (used when choosing the saved response from a list of others), and the actual content that will appear when you choose this saved response on ticket replies, or when opening tickets.
When choosing the "Type," you can designate where the saved response will appear: either when replying to tickets, or when opening tickets in the admin section.
Saved responses will be reflected within the ticket body section, on the appropriate page (designated by "Type"):