Audit checklist for on-site supplier audits

I'm revamping my company's audit program and documents. My company is BRCGS Packaging materials and ISO 9001 certified, but we have various suppliers that aren't BRCGS or ISO approved, are in various types of industries or are new suppliers to us. I need to create a supplier audit checklist that is general enough to use across these industries and qualifications, while still hitting all of the major categories as per BRCGS requirements. Does anyone have any suggestions on creating an audit checklist for on-site supplier audits?

Sometimes a generic document becomes too basic, I've looked to do something similar for BRCGS Food. Start by categorising your suppliers into groups, who has certification, who doesn't; that way you can do a very basic risk assessment. It may be that a basic Supplier audit questionnaire is for low risk suppliers with certification, but more in depth and a factory/site visit to audit with a more detailed report for higher risk suppliers. 

How many do you have?