I had the most amazing tax instructor back in college (a million years ago).  He said the best advice he could teach us - open up the tax forms instructions supplied by the IRS and every state.  You'll be amazed at what you can find in there.

Filing Your Tax Return

Attachments to your tax return.

Do I need to attach a copy of federal Form 1040 or 1040-SR?

Other than Schedule A (Form 1040) or Schedule B (Form 1040), did you attach any federal forms or schedules to your federal Form 1040 or 1040-SR?

If No, do not attach a copy of your federal Form 1040 or 1040-SR return to Form 540.

If Yes, attach a copy of your federal Form 1040 or 1040-SR return and all supporting federal forms and schedules to Form 540.

Exception: If you did not itemize deductions on your federal tax return but will itemize deductions on your California tax return, complete and attach a copy of the federal Schedule A (Form 1040) to Form 540.

Do not attach any documents to your tax return unless specifically instructed. This will help us reduce government processing and storage costs.