If you still have the lipstick you bought three years ago, chuck it! Unless you're keeping it for an upcoming science fair or sentimental reason, the lipstick has got to go. Unlike food, makeup and skincare products don't have an expiration date. That doesn't mean your concealer can last you until you're well into your forties; the FDA just doesn't have any guidelines for makeup care.     First, organize your makeup bag. Anything that is dried-out or smells funny should be thrown out. Sometimes it's hard to tell if it smells funky because makeup sometimes smells strange to begin with. Use common sense when it comes to makeup care: if it smells funny to you and you can't remember how long ago you bought it, put it in the trash. Anything that has a broken case or missing cap can still be salvaged if you use it often. Here's a makeup care tip: products with missing caps, like eyeliner, can be put in sandwich bags. If your foundation bottle is cracked, buy a new bottle. Products that look…