The first point is hazard identification: walk the premises, check the records and talk to the people who use the space, because nothing later in the assessment can catch a hazard this stage misses. The second is deciding who could be harmed and how, named as groups, with particular care for anyone more exposed because of age, health or mobility. The third is evaluation: how likely each harm is, how serious it would be, and whether the existing controls hold the risk to an acceptable level.
The fourth point is the written record. It should capture the significant findings: the hazards, the people affected, the judgement reached and the actions planned, each with a name and a date attached. The fifth is review, because an assessment describes the premises on the day it was made; it needs revisiting after material changes, after incidents and near misses, and periodically in between, on a cycle a competent person has matched to the risk.