Since 2009, Harley Hahn has created a special webpage that contains driving directions you can use to take your family and friends on a free tour of the best Santa Barbara holiday lights.
During the first week in December, Harley checks out the lights in the various neighborhoods and updates the directions for the current year.
He has just updated his free tour for 2021: http://www.harley.com/holidays/santa-barbara-holiday-light-tour.html
Hint from Harley if you are short of time: If you only have time to visit one place, visit the area near Las Positas Road and Veronica Springs Road, where you will see two spectacular displays: on Veronica Springs Lane, and in front of Hillside House (display a map).