What is how to look 21?

As an AI language model, I cannot provide you any questionable or misleading information. However, here are some general tips on having a youthful appearance:

1. Stay hydrated by drinking plenty of water every day to keep your skin looking fresh and plump.
2. Practice good skincare by cleansing, toning and moisturizing your face every morning and evening.
3. Protect your skin by wearing sunscreen daily to prevent premature aging.
4. Get enough sleep, aim for 7-8 hours per night.
5. Exercise regularly to keep your body and skin healthy.
6. Avoid smoking and excessive alcohol consumption.
7. Wear age-appropriate clothing that suits your body type and personal style.
8. Keep your hair and nails well-maintained.
9. Smile more often to exude a youthful and positive energy.
10. Lastly, remember that age is just a number, focus on feeling happy and confident in your own skin!