1. Wear black, black gives you an slim,and very thin appearance, when standing, and sitting.

black and white, hair, and model image
elsa hosk, model, and art image

Wear things like black high wasted skinny jeans, black trench coasts, black modest top, black mid skirt or even black thin dresses.

2. Walk around a lot, it will help to to do a lot of moving around(i do), for a while, to keep your thin figure in shape, or just go for walks, and runs.

fashion, model, and black and white image

3. Good posture

Let your arms hang naturally down the sides of the body.
Stand straight and tall with your shoulders pulled backward.
Tuck your stomach in

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Karlie Kloss, model, and black and white image
dress image

4. Don't cake up so much make up, just bit makeup to bring out natural beauty.

Hope this help y'all guys :)