Jayapataka Swami: As soon as your mind deviates and thinks of some impure activity, you should withdraw your mind and put on the pastime of the lotus feet of Lord Krsna, and that is where you need to discipline your mind, that the mind should stay fixed on Krsna and never forget Krsna, and not let the mind think of such things. Srila Prabhupada said that we always have Krsna on one side and maya on the other. Krsna means seva and maya means sense gratification. So we would like to do service for Krsna, we avoid doing sense gratification, which has no connection with Krsna. Hare Krsna!