here are two russian idioms i like the best
он роботает спуся рукава which translates as he works with lowered sleeve's
but is a idiom used to say someone is lazy.
я собираюсь показать, где раки зимуют it translates as i am going to show where the crayfish spend winter.
this can be used as the english way
to give a peice of your mind to someone