Wearing heels but not too high, 3-4 cm heels are optimal and don't make you suffer while walking in the city
Accentuate your natural nice features, don't try to hide something or make it look to fake and made up. Natural light materials, light not shape sculpted underwear. Lace bra and white classic shirt is an ideal example.
Don't limit yourself for just skinny jeans. Straight leg models or slight flair with high waist looks original and fit more body types than skinny legins type ones.
Add color in your outfit but not too much. Do not go for more than three different shades in one look.
Don't be afraid to make investment purchases. Vintage and timeless elegance is what french value a lot. Classic pieces last you longer and it is easier to stick to your style rather than blindly follow trends.
Accessorize. French are famous for using accessories in everyday efortless outfits. Scarf in light neutral color or pop of bright color that you know fit you. Gloves, few pairs for different seasons - warm winter gloves, long opera leather gloves gorgeous in white or black, elegant wrist gloves just to add a style detail to your look.