I have a custom cloth cover for the dust cover of my old SOTA Star Sapphire. I don't recall who made it, but it's nice not to have to dust the turntable's acrylic dust cover often.
I use a combination of my vacuum and impregnated dust rags for dusting the gear racks. There are some tight spaces on the sides of the gear that is in enclosed cabinets that can be hard to reach, especially for gear that has rackmount facies, but that dust on the shelves is not all that harmful.
An important bit of occasional maintenance is to open the covers of my amps and blow out the dust inside. I've only done this once in the 35 years I've had them. I keep clear plastic covers on them when they're not on, so that reduces the dust accumulation externally and internally.