Instagram. This is very sarcastic but sometimes true. Though it isn't what you asked for. "Being beautiful" is something that doesn't exist as such for itself. It is a state of an interaction between a subject and its beholder. So becoming beautiful might just need the right beholder, the right subject, the right combination of both. We all agree upon certain ingredients for beauty but we also widely differ even in the most basic things. So the question for "how" to do it is almost impossible to answer.