The Sunset Hills Trail is easily accessible off of Erbes Road in Thousand Oaks, just 7/10ths of a mile north of Sunset Hills Boulevard, just past Fernleaf Court.
This is a pretty easy mile or so trail that takes you past the Bard Lake Reservoir, which is of course is fenced in but you'll be treated to its beauty as you make your way up. Lake Bard is owned by the Calleguas Water District for storage of up to 10,000 acre-feet (3.3 billion gallons) of water used to meet peak summer demand and emergency requirements.
In fact, most all the way up this fairly gentle, hilly slope, you'll get some great panoramic views of the entire area, including the Conejo Valley, Simi Hills and looking west towards Camarillo/Oxnard.
The Sunset Hills Trail is maintained by the Conejo Open Space Foundation. More information at www.cosf.org/website/html/sunset-hills-trail.html.
To extend your hike, take the additional loop in the shape of Maine (kind of) either clockwise or from the first juncture or counterclockwise after cresting the hill.