Whats the best way of preventing acne and losing it without all this pro-acne stuff?

The best way you can do for Acne prevention is, have enough and right food.
For acne formation, your food & your habits matters a lot. Even if you look fit.
If the spicy food, Junk food & fast food intake is there, then definitely you will get acne. So avoid eating these food. Eat more green veggies , Salad etc.

Drink plenty of water. You can also have a green tea at least once in a day.