SOPs without the corporate theater
An SOP isn't a binder. It's the answer to 'how do we do this here?' written down once.
Start with the tasks you redo most
The first SOPs to write are the things you explain over and over: opening the shop, closing out a job, handling a refund. Not the heroic edge cases.
Write it like a recipe
Steps, in order, in plain language. A new hire should be able to follow it on day one. If you need a flowchart, you're solving the wrong problem first.
Make them living documents
The team that runs the SOP should be allowed to edit it. SOPs nobody updates rot inside six months.
Take your version of this question further
This is one operator-tested angle on the question. Your shop, your size, your trade, and your team change the answer. Ask your specific version inside Ask a Shop Owner to get a response grounded in how owners like you actually handled it.