When we talk about "frost" on a cannabis plant, we are talking about trichome production. The more trichomes that are on a plant, the more frosty a plant looks.
Maine420medgrower is well-known on YouTube to grow some frosty cannabis plants. He even has an entire video series called "We Grow Frost."
What does he do in order to get those frosty plants?
Check out his video here: