The standard has moved on
OHSAS 18001 has been withdrawn and replaced by ISO 45001. New workplace health and safety applications should refer to ISO 45001:2018 rather than the older designation.
Start with the risks in your workplace
Document hazards, assess risks, identify applicable obligations and involve workers in safety decisions. Operational controls, emergency preparedness and incident investigation belong in the system.
Make it part of daily work
Training, participation and regular review matter more than a document kept in a drawer. Bring safety records and a clear scope to your application, and plan for surveillance throughout the certificate lifecycle.