When the postie comes, I'll be building a PC for the first time in years. What are the do's, don'ts and tips nowadays?

Obviously classics like RTFM, plan ahead and retrieve any dropped screws are evergreen.

Things I believe are true: tighten your CPU cooler screws evenly (like putting on a car tyre), all screws should be no more than finger tight, build in a dust-free environment.

What about grounding yourself? I remember reading that the danger of this was way overstated and e.g. anti-static wrist straps were a waste of money. Is building in a case that's plugged in (but powered off) enough?

I've seen recommendations to build outside of the case first to test components - is this good advice?

Anything else?