A management system needs to describe how the business actually works. For ISO 9001, that includes understanding the organisation, focusing on customers, controlling processes and improving performance.
Start with the reason
Bring the tender wording, customer requirement or operational problem. Clarify the relevant standard and scope before creating documents.
Look for evidence in everyday work
Responsibilities, process records, training, customer feedback and actions taken when things go wrong help explain how a system operates. The detail should fit the business and the applicable standard.
Review before external assessment
Internal audit and management review help identify gaps and opportunities for improvement. Independent certification is a separate process; consultancy support does not itself award a certificate.
Sources: ISO overview of ISO 9001 and ISO 9001 Auditing Practices Group. Requirements should be checked against the applicable current standard and certification scope.