One of the cornerstones of tech writing is a style guide.
Style guides provide a foundation of consistency in documents.
There are several popular style guides. A well known guide is The Chicago Manual of Style. These popular guides suffice for many writers.
Often custom in-house style guides are written. Minimally a style guide includes writing style but often includes document design — layout and formatting.
In addition to editorial guidance, an in-house style guide defines the business style of documentation and helps establish a company identity. Company documents will be consistent and have a similar layout.
Writing an in-house style guide is not a massive project. The popular style guides are useful as a template to create a local style guide. Massage the in-house content to fit local needs.
While some people might argue that a style guide is only a guide, in practice the guide is a cornerstone of writing projects. The guide should be revised and tweaked as needed. Using the style guide in this manner avoids debates and conflicts.