LPs get cleaned on acquisition, given a new inner sleeve, and then cleaned again whenever I think they need it. A good clue is when flecks of dust will not blow off despite a treatment with an anti-static device.
A soft stylus brush before each session, and a carbon fibre brush with one drop of stylus solution about every week (exception: no wet brush gets used on the Deccas, with no cantilever it is too easy for liquid to get inside the cartridge).