Refinement isn't about abolishing all risk, removing any uncertainty and figuring out all details.
After all, if we could do that, we wouldn't need Scrum or Agile. We could duke it out through fancy documents with clear thinking. Wouldn't that be awesome?
To some degree, we're supposed to figure things out as we do the work. The problem isn't what we know, it is what we believe to know that is untrue and what we don't know.
Talking about all the steps you intend to take before starting isn't good enough.
Every step you take helps shape the way.
Don't delay your journey unnecessarily by talking about imaginary problems and going for that magnificent planning homerun.
Your plans will have to change and you can only discover the extent they are wrong by actually doing the work.
Over-fitting your plans means they will become anchored in speculation and rooted in your imagination. You will become locked into plans that don't bring you closer to your destination.
Anchor your plans to reality by starting with humble plans that are shaped during the journey.
Refinement is about establishing common understanding and having reasonable confidence you believe you will be able to pull it off. No amount of preparation can provide an absolute guarantee.
It's not about preventing the failure to predict as it is inevitable that will happen. It is about making sure you're making the most progress you can.
Don't delay hitting the bat by going for a victory on paper.
It's the steps that go in the right direction that count, not the ones you believe to be going in the right direction.
Some teams tend to begin work too early, others tend to begin work too late, and Scrum Masters/ Coaches/ Product Owners/ Engineers constantly need to read the team and adjust.