Beauty comes from within. It is a state of mind, a state of soul.
People can have physical flaws, physical defects, physical deformities and be attractive, happy, married.
People can have physical perfection and be sad, lonely and repulsive.
Caring for the soul, living in the love of Christ, taking Him and His compassion with you every day is the beginning. Treat every person you encounter as if they are Christ.
A positive attitude, intelligence (does not require a $$$$ degree, read books, real, thick books), wits and a sense of humor are next.
Last is taking care of your physical appearance. For everyone:
Clothes that fit you, are in good repair and are clean. It does not cost a ton of money. Better to have 7 items in your closet that are of good quality and fit than overflowing with just stuff. (For instance, I have one pair of black cigarette pants that I wear to work, to Mass, 6 days per week. I take care to wash them so they don’t fade and I do not put them in the dryer. I’ve worn them daily for over two years and they still look as good as the day I bought them.) Think timeless classics when you buy clothes. Shop second hand or the sale racks at high end stores. Do tailor clothes so they fit your body correctly.
Hair styled and groomed
Care for your skin (a gentle cleanser and a cotton wash cloth every day + an inexpensive moisturizer),
Teeth clean and breath fresh
For women YouTube videos can teach you how to apply cosmetics (and there are subtle corrective things that men can do, like use a green stick to conceal redness from acne or roseacea)
Make sure your facial hair is under control (for men and women, little things like grooming your brows, trimming nose hair - and ear hair for men. For women tweezing that upper lip hair as well as chin hairs)
Men and women, make sure your nails are trimmed, filed, clean, cuticles clipped so you don’t give in to biting them. Use an old toothbrush as a nail brush to really clean your nails.
Strong handshake. Confident speaking voice. Good posture (don’t slouch).
Drink water. Eat food that is as fresh and as un"manufactured" as you can afford (and learn good table manners!)