California has some common regulations about filing a mechanics lien. However, you will also need to grasp county specific requirements. I came across an article  that provided some simple, yet useful information. As it relates to the very litigious Los Angeles County, here is a summary of simple things to do:
Do You Need a Preliminary Notice?
If you did not directly contract with the project owner, you must provide a Preliminary Notice within 20 days of first providing labor and/or materials to the project. If there is a construction lender, a contractor with a direct contractual relationship with the owner needs to only serve a preliminary notice on the lender. Make sure to send the Preliminary Notice via certified mail, return receipt requested.
Timely File Your Mechanic’s Lien.
You must have the right to use a mechanic’s lien. If the work you did was not consumed in the improvement, or used to improve the property you won’t have a right to a mechanics lien. If your contractor’s license in not in strict compliance with the Contractors State License Law, your rights to a mechanics lien may be impacted.
A direct contractor must record its lien claim after completion of the contract, and the sooner of either 90 days after cessation of the work or 60 days after the project owner records a Notice of Completion or Cessation. A subcontractor must record its mechanic’s lien after cessation of its work and the earlier of 90 days after completion of the work or 30 days after the owner the project owner records a Notice of Completion or Cessation.
Remember that you will also need to prepare a “Notice of Mechanic’s Lien” and serve on the owner, the lender or the general contractor.
Additionally, a “Proof of Service Affidavit” is required to be recorded with the mechanics lien to prove that service of the lien and Notice was made. Generally, service must be done by registered mail, certified mail, or first-class mail, evidenced by a certificate of mailing, postage prepaid. No longer is a courtesy copy sent from the county recorder’s office going to be good enough to put the owner on notice.
File the Mechanics Lien in person to ensure immediate recording. File your Mechanics Lien at:
LA County Recorder’s Office
12400 Imperial Highway
Norwalk, CA 90650
Use letter sized paper and not legal.
Provide extra copies and a self-addressed envelope to the Clerk.