I cover the platter to keep dust from cross-contaminating my records due to accumulation on the platter. I use an unloved Charlie Rich album given to me as the platter dust cover (I also have a "Benji's in Love" (remember that movie mutt?) picturedisc for this purpose). I also use an aluminum foil "hat" to cover the pivot area of my tonearm (see, tinfoil hats are not just for crazy people). Once in a great while, I wipe away the dust accumulating elsewhere on the plinth and other surfaces (I don't want the table's suspension springs to sag from the excess weight). Otherwise, I pretend that "dust damping" improves the sound quality.
dust protection for turntables
Most higher-end turntables do not have built-in hinged covers. So what do people use to keep dust off their TTs when they’re not being played? Those large molded plastic covers that fit over and around the whole plinth? A silk scarf from Hermes? What's the most ingenious solution you're used or come across?