First of all, always always always prime your face! This will prevent creasing and help your makeup stay on all day :) If you have a bluish-purple tint under your eyes, apply a salmon colored concealer and gently pat it under your eyes with your ring finger. The salmon color will correct any blue/purple colors. Since this is such a different color from skin tones, it might appear orange under the eye but don't worry, we'll fix that later! A great product to reduce bluish tints is Eve Pearl's Salmon Concealer.
After you apply your foundation, apply your concealer in an upside down triangle shape. I like to apply this with a damp Beauty Blender. You want to find a concealer that is much lighter than your skin tone. I have a medium skin tone and I use a light or fair concealer. My favorite concealer is Tarte's Smooth Operator Amazonian Clay Waterproof Concealer in Light. The consistency is so buttery smooth and it blends flawlessly. If you don't want to spend that much, a great dupe is Revlon's PhotoReady Concealer in Light
To set your concealer, I would recommend using a yellow-based powder (for darker skin tones) or pink-based powder (for fair/ivory skin tones). Many people use a transleucent white powder under their eyes which can make their face look white casted in pictures. My favorite powder that won't give you that white look is Ben Nye's Luxury Powder in Banana. I also pat this in with a damp Beauty Blender. Ben Nye's products are used for photo shoots and movies (and is also used by Kim Kardashian), so it will stay put and stay matte all day!
Last but not least, two of my friends here on Blogspot, Jenna and Lynette are hosting a Link Up on February 1st called Once Upon a Date Night which bloggers will give date ideas, outfits, makeup, etc. I linked it by my banners on the left -- go check it out!!