Your warm (repeat: warm) shower or bath hydrates your skin, and it prepares your skin for shaving with a reduced risk of skin irritation. The softer your hair is, the easier it is to shave off cleanly.  Let your hairs soften and stand up from the warm water. The moisture and steam from your bath or shower cause your hairs to become soft and to raise against your skin. Softer hairs that are raised against your skin shave much more smoothly than areas that are not prepared for shaving. Hold a warm, wet washcloth to the area for at least 5 minutes if you don't have the time or resources to shower. Many people are guilty of skipping this super-imperative step. In fact, you should be doing it both before and after you shave. It may seem like a waste of time, but your skin will be smoother and less prone to redness and irritation. When you exfoliate before, it aligns your hairs for a uniform shave and sweeps away the dead skin, allowing for a closer shave. When you do it after, it unclogs your pores (from the shaving and creams, etc.) and prevents ingrown hairs (that cause razor bumps). More on the specifics of creams and the like later, but using something to hydrate your skin is AN ABSOLUTE MUST. Do you feel like you're being yelled at? GOOD! ALWAYS USE SHAVING CREAM. Crystal clear, right? Do not ever shave with just water. Soap and water is okay, but a cream designed especially for sensitive, to-be-shaved skin is best. And when you shave the same area twice, be sure to reapply. Use razor strokes that go downward. Applying pressure with your razor against the grain of your hair causes irritation and bumps. Generally, this means down. Yep, shaving against the grain allows for a closer shave, sure. If that's what you want, go for it. But the likelihood of your skin getting irritated increases exponentially when you do so. The two sort of work in tandem, actually. When your stroke is short, you tend to be lighter on your skin. If the stroke is too long, you feel as if the razor dulls and you need more pressure to...

How would you rephrase that briefly using Vietnamese?
Cạo lông sau khi tắm nước ấm. Tẩy da chết, tẩy da chết, và tẩy da chết. Luôn dùng chất bôi trơn khi cạo lông. Cạo theo chiều lông mọc. Đưa những nhát cạo ngắn và nhẹ. Rửa da bằng nước lạnh và thấm khô.