Dusting first makes some sense, granted. I have a Dyson and it sucks up everything, but my old vacuum used to throw out a lot of dust because it sucked (because it didn’t suck?) so I got into that habit.

As for what makes up a made up bed, the point isn’t necessarily to tuck everything in tightly — though I do that, myself — the point is more about “looks good” than performs a valuable function, so that the tidy appearance cascades to other areas. If you prefer an un-tucked bed, I’d still recommend straightening it up a bit, keeping the sheets folded over in a nice line or, per Tali’s suggestion, open up the bed and keep the blankets and duvet nicely layered at the foot.