How do I prove capacity or lack thereof for conversatorship?

That proof is made by applying the analytical structure of Prob C §811 to the facts of the proposed conservatee’s life. The best practice is to do this in the initial conservatorship pleadings. A verified Petition for Appointment of Probate Conservator (Judicial Council Form GC-310) and the accompanying Confidential Supplemental Information declaration (Judicial Council Form GC-312), if uncontested, will be accepted as evidence. See Prob C §1022. Thus, if the initial pleadings present clear and convincing evidence of the need for a conservatorship and are uncontroverted, the court may order the conservatorship without hearing further evidence. Prob C §§1022, 1801(e).