Answer:
Ensure your face is clean and resist touching/picking at your face.
Explanation:
It all boils down to your pores and whether or not they are clogged. They are clogged most commonly with sebum, but also dead skin cells. The oils from your hands, along with other things such as pollution and other gasses get in your pores and trap your natural oils from being free.
The bump you experience as a pimple is just your sebum trying to get out. Which is why its very important to keep your face clean. Face cleansers are helpful, too, but all you really need is warm water to open your pores up, then splash your face with cold water to close them.
It's also best to limit what touches your face, or at least make sure it's clean. So wash your pillow cases regularly, if you wear any masks regularly keep those clean too.
Touching your acne and popping them only make them worse. Not just appearance wise, but they spread the dirt and goo trying to escape to the other nearby pores. The point is to keep them nice and clear, so don't mess with them.
