The best moveset for Clefable in the current competitive meta typically features the moves Follow Me, Moonblast, Protect, Helping Hand.
In the Pokémon Champions meta, Clefable can be countered by exploiting its weaknesses (poison 2x, steel 2x) and using effective check/counter teams.
The best item for Clefable is typically Sitrus Berry, based on high-level tournament and ladder stats.