Filters.
I have never used that filter, but I know firsthand how important good filters are. Pleated filters are good, and blue fiber filters aren't. There are many different pleated filters and other filters beyond pleated ones, it is a good idea to use better ones rather than inferior ones.
A good filter will help reduce dust and allergens in the building but it will also help the HVAC system age more gracefully. Dust buildup inside the air handler/furnace and ductwork can be surprisingly thick. The more dust in the system, the less efficient the system is. Every few years it is a very good idea to have the ductwork and especially the air handler/furnace/AC coils cleaned. Even if your system does not utilize the most efficient components available, keeping it clean will improve its efficiency.
Sort of like driving an old inefficient car, by keeping the tires properly inflated, you can improve your fuel economy, sometimes by quite a bit.
Proper maintenance makes all the difference in the world,
Dave