Most procedure manuals are written once, filed, and never opened again. They fail for the same reason: they describe how work should happen, not how it does.
One page, one task
A good procedure covers one task and fits on one page. It starts with what the task is for, lists the steps in order, and says what done looks like. If it needs more than a page, it is probably two tasks.
Write it with the person who does the work
The person who does the job every day knows the shortcuts, the exceptions and the things that go wrong. Write the procedure with them, in their words. People follow what they helped build.
Test it on someone new
Hand the page to someone who has never done the task. Every question they ask is a missing step. Add it. When a newcomer can follow the page without help, it works.
Give it an owner and a date
Every procedure needs one person responsible for keeping it accurate, and a date to look at it again. Without both, it drifts away from reality until nobody trusts it.
Ten good one-page procedures will do more for the business than a manual nobody reads.
Start with the tasks that matter most to your customers, or that carry the most risk. Write one a week. In a quarter, the work that matters most no longer depends on memory.