There are several items you need to do when serving a proper 3 day pay or quit notice or a judge can rule against you in court and you will lose the case.  This means you will need to start over with a new unlawful detainer case wasting your time and money to evict a tenant.

On the 3 day notice, you can NOT include late fees.  ONLY the rent amount that is past due.

You will need to keep a log showing the dates and times you tried to locate the tenant at home.  If they are home, you serve them the notice. If they are not home and you have tried at least twice… you can serve this to an adult over 18 years of age as a substitute  or you may post on the door and take a photo of this for your proof of service.  If you post on the door, you will also need to mail this certified mail with a tracking number to show the court you mailed it.

For LA County, you need to also include in the notice the number of bedrooms this unit has that you are service this notice on and then submit this notice to the LA Housing dept. (this is can be mailed to them or submitted to the LA County Dept. of housing online.

Now you can finally take this POF (Proof of Service) and the copy of the 3 day notice to  an eviction attorney to handle the rest.  They will file with the courthouse, get a court date and if all goes well (some tenants will request a jury trail)…then you will win the case.  The judge will issue a writ of execution that you can then hire a county sheriff to schedule a final lock out date.