Dress it up with feminine tops. Most women's navy double-breasted blazers feature deep-V necklines perfect for showing off feminine accents beneath. Opt for a lace-trimmed camisole in a creamy pink or off-white color to create a subtle but elegant color contrast. Be a bit bolder with a dramatically ruffled collar on a cream-colored silk top. Button it up for the office, and leave it open for lunch.
Go casual with rocker-girl chic skinny jeans. Dark-wash skinny jeans are a near-perfect color match for a navy blazer, and light-wash skinnies add a striking color contrast. Keep it simple with a pair of white sneakers and funky laces, or dress it up a bit with a pair of black leather ankle boots.
Skip the undershirt altogether, and opt for a sexy silk scarf instead. If the hem of your blazer hits the hem of your bottoms, you don't need an undershirt. Instead, cover up a deep neckline with a flirty patterned scarf tied in a simple knot and draped down your torso. Keep the color palette neutral, with brown, black, cream and gold, but go wild with patterns to add a little spice to the outfit.
Add some structure to a flowing dress with a short-cropped navy blazer. If you're rocking a nautical striped cotton sundress, a closely tailored navy blazer that cinches in at your waist and flares slightly toward your hips breaks up the pattern while highlighting your waist and bust.
Play up your little waist with a decorative belt. A cream-colored leather belt contrasts with the navy to create a visual delight that slims down your waist, while a wide black or navy satin ribbon tied in a romantic bow adds a feminine touch to your attire.
Draw attention to that sexy neckline with bold, chunky accessories that play off the structured shape of a double-breasted blazer. Aim for dramatic contrasts, such as necklaces made from green resin with gold flakes, or keep it coordinated with antique gold pendants and earrings.
The success of your navy blazer depends largely on tailoring. Stick to blazers that are fitted to your body, cinch at the waist and stop just above your hips. Avoid bulky shoulders or high pockets, which add width to your shoulders.