The russian oil refineries that have been very successfully attacked seem to meet the definition of this. One obviously useful thing for the Ukrainians to do is to cut off the supply of refined diesel and petrol to the Russian army's vehicles.
If this also has the effect of causing significant pain to the russian domestic economy (lack of fuel for general civilian vehicle uses of all types), it has the additional benefit of being a very real and public pain point causing dissatisfaction with the average russian civilian.