I am not originally from California, but my siblings moved there after I started med school on the East Coast (where I am from). I fell in love with the state when I visited them on vacation, and I did my best to try to match there.
When I interviewed for residency programs there, they would ask me about ties to California. I ended up matching back on the East Coast- I really do think geographic bias plays a big part in program directors' rank lists (esp if you're a mediocre candidate in other ways- I was). They want to make sure you have a support network/would be happy to live there for years.
I think certain things would have helped my cause:
-permanent address in California
-good reason to be in the state (i.e. your partner lives there, parents live there, etc)
-be as competitive as you can be for residency apps- consider doing away rotations at schools and get to know the department
-if there are faculty members at your school who have connections to California, ask them for help
-applying for a less competitive specialty can give you an edge
btw, I was successful in getting my prelim year in Cali, but that was all.
good luck and I hope that helps.