Help, I need an Enterprise Patch Strategy

I am interested in developing an Enterprise wide patch strategy that will provide the operations team with guidance on what to patch when and how to go about it to ensure that risks are recognised and managed. As a result I am looking for others that have done this and used a fit for purpose or best practice approach and is willing to share expertise and perhaps findings/output. I am not interested in buying a tool to help with this rather to provide verbal guidance and set expectations.

Please give me a hand rather than reinventing the wheel