First, the description: which premises, activity or task the assessment covers, and, as usefully, what it excludes, so nobody assumes protection that does not exist. Second, the hazards, specific and located: "cardboard stored against the electrical intake in the ground floor riser" does work that "combustible storage" never will. Third, the people who might be harmed and how, set out as groups, because a control that protects able-bodied staff may do nothing for a resident who cannot manage stairs.
Fourth, the evaluation and controls: for each hazard, how likely the harm is, how serious it would be, what already limits it and what more is planned, with an owner and a date against every planned action. Fifth, the spine: who wrote the assessment, when they wrote it, and when and under what circumstances it will be reviewed. That final line turns a static document into a managed one, and leaving it off is among the common mistakes in risk assessments.