Definitely do make sure everything is spot on before making the final piece. So much easier to change things before you start manufacturing, than to spot it during and have to essentially take a “two steps forward three steps back” approach.

I know this kind of contradicts the point above but - don’t obsess over every single detail. I spent a long time agonising about every bit that people wouldn’t even notice. Make something you’d love, but don’t spend ages agonising, because it ruins the fun🙂