Proper documentation sticks to the facts. Don't treat your notes of conversations with employees as a personal journal, where you express opinions and share emotions. Documents can become public record in a court of law, so keep clear, professional notes. Write in a detached tone, as if you're an outsider detailing what happened from a safe distance. Focus on quality of work, behavior and conduct, attendance and availability. Do not attack and employee's character or become an armchair diagnostician by focusing on your employee's psychological make-up.
Include exhibits and other support to build airtight documentation.
Examples: 1) Insert complaint letters from customers as evidence of an employee's poor service delivery. 2) File copies of timecards as proof of an employee's chronic tardiness. 3) File a copy of a consultant's analysis of an employee's poor productivity.