A really nice ride we have done several times.
We usually start in Carpinteria, but here are some directions from Ojai.

There is a really nice bike path separate from and running parallel to Hwy 33.
You can pick it up at Hwy33 and Hwy 150.
The bike path heads west all the way into Ventura.
Then in Ventura there is another bike path that heads north along the beach.
Eventually it turns into a frontage road and then you have ride on 101 for a bit into Carpinteria.
Then take Casitas Pass Rd east (Hwy 150), some climbing here.
Go around Lake Casitas and back to Ojai. I think its about 40 miles.

Enjoy