How do I send an email to a technician when a new ticket is opened?

1. Create an Automation Rule called Create a Ticket. See here for more information.
2. In the Create a ticket rule, in the Actions section, in the Action Type drop-down, select Send an email to Technician. Note that this is based on the existing New Ticket Created Email Template. (For information on how to create email templates - see here.)

Click Add.