We invested in a roomba-style robot that has actually been fantastic. Less for the "I am lazy and don't want to hoover my flat" and more for its ability to reach places I can't easily. Keeps under the sofa/bed/etc pretty tidy.
Also change the A/C filter regularly never hurts.
to add to this, do you live near a construction site or a busy street? This can greatly increase the level of dust. if not, get fresh air circulating through windows if possible and avoid lighting candles or smoking inside.
When my hvac broke and was replaced they put in a 4 inch wide filter box, instead of the 1 inch it was before. They said it allowed 5-10x the amount of air to go through and that seems true. Airflow from the vents is way better and I've noticed less dust, plus the filter doesn't have to be changed as often.
Removing and adding the sheet metal on the intake for the furnace filter isn't easy, but in case you have the skills or know someone that does it made a huge difference. Or build one of those box fan filters, if you look up Corsi-Rosenthal box you'll find instructions online.