Clear language is not a set of rules. Clear language is a process: thinking, planning, writing, designing, testing, revising.
The first step (thinking) starts with considering your reader, your purpose and the intended impact of your document.
Who will be reading this material? What do your readers already know or understand about your subject? What is their:
If you can, work with a group of people like those you are writing for. Find out what they want to know. Ask them to review draft material.
Why are you writing this document?