Just want to say that this is a fantastic answer. Pay attention to the parts about printing/downloading stuff. There are huge parts of America where you won’t get a reliable cell signal sometimes for hours.

I’m having a hard time envisioning a situation where testing my code requires a bunch of unused variables. Just don’t declare the variables until you’ve started writing the code that uses them…

Why in the world would you want to develop something that doesn’t follow the coding rules required by your org, just so you can go back and fix everything before submitting a PR? That’s just extra work.