Actually these guys are mean... just ride up Newport Coast and go over the back down to Bonita Canyon. If you can somehow find the Shady Ridge Bike Trail off Shady Hill, take that through the Shady Ridge private developement and it take you down to Sand Canyon. Take a right at Quail Hill. Iffin you are so inclined you can follow the signs and turn right onto Laguna Canyon Rd and take that back down to PCH (actuallly we usually turn up Cliff Drive and take the back way but too difficult to explain now). Turn right onto PCH and have a nice long rolly ride back up to Jamboree.
If you check the BCI website - look for rides, check Sunday rides you might be able to locate a route slip to your liking. I'll go check and see if something is there you can do.
Oh getting back to the above route. Instead of Laguna Canyon South turn left (actually you go around a traffic circle) on Laguna and take that to Alton, take Alton all the way back to teh San Diego Creek Trail get on it and go South towards the beach.