Hi Pam
Going east on 150 through Ojai you end up going up the Dennison Grade and down into Santa Paula. Santa Paula. from there you can take flat streets back to Ventura or reverse your course and go through Ojai again.
Going west on 150 you will end up at the beach and it is a fairly enjoyable climb. Again, if you want to return via the flat lands it is possible.
In either case, if you return via the flat lands, it would just be easier all around if you started in downtown Ventura.
For some additional climbing, not steep just long, go north on 33 as far as you want.