Baal Shem Tov (the original below) advises us about a change of paradigm when we are triggered by an object of our lust. Contemplate about the source of this person's beauty: Isn't it G-d Himself? And if so, why settle for a mere part (chelek), why lust after an external beauty or pleasure, when I can choose to lust after the Source of All pleasures?
When we lust, we are really looking for "connection" with something beautiful. But we will never find it in flesh and blood, it's like a mirage in the desert that the thirsty person is sure that it's water, but when he gets closer and tries to take it, there's nothing but hot-air there.
The beauty and connection we seek are really the vibes of our souls, yearning for connection with the source of all beauty. Yes, this isn't always an easy frame of mind to maintain, it takes EMUNAH. But the more we work towards this Emunah, the more success we'll have in staying away from looking at things we shouldn't and lusting after them.
As I was contemplating this idea, Hashem showed me this Mishna: