A few years ago, almost nobody asked this question. But when California lawmakers adopted the Uniform Premarital and Marital Agreements Act, everything changed. The UPMAA streamlined rules and procedures. Now, if you have been married before, you should at least consider a prenup.
You just asked a mouthful. Generally, any property acquired before the marriage or by gift is separate property. Most everything else is community property subject to a mandatory 50-50 division. These waters seem clear, but issues like transmutation and commingling muddy them considerably.
Mediation is the most common form of alternative dispute resolution. If both parties work with a mediator in good faith, mediation is usually successful. Collaborative law is gaining popularity. In this litigation alternative, the parties never go inside a courtroom, even for a pretrial hearing.