I went to Cal straight out of high school, but applied to a smaller college within Cal, College of Natural Resources. I actually was more interested in the majors offered by CNR rather than those in Letters and Science. Anyways, my grades were excellent (weighted it was over 4.0), but SAT's were mediocre. But since I applied to CNR, which isn't as competitive as L&S, I got accepted. It just worked out that I really wanted to be in CNR. But that's one route you can try to get your foot in the door.
Another way to get in is to be very convincing as to what you want to do after college. If they see that you are passionate about being, let's say an architect, and you have some "real world" knowledge about it, that helps too. My advice would be to try to find an internship in the field that you want to go into. Better yet, find that internship at Cal/UCLA and it might help even more.
Hope that helps. Go Bears!