Something casual. Something flirtatious. Something so he can see your curves but still leaves something to the imagination. Something so that he can dream about the way your curves are going to feel. Nothing that is too in-his-face. When it comes to fashion, we all have our own personal style and what works for one woman might not work for another, but it's pretty safe to say there are some things that just don't work for anyone, especially on a first date.
Lace is great, but not if it's showing your midriff. That's just a little too much distraction going on. Guys don't like a lot of heavy makeup, but they do appreciate that you look very polished. Too tight looks odd, and too baggy looks sloppy and like you don't care about the date. Aim for a happy medium that's just right for your body type. Make sure your pants fit well around the waist - you should be able to put three fingers comfortably in the waistband, but not much more - and that the hems hit around the bottom of your ankles. Shirts should cover your waist without falling past your butt. When you're picking out a shirt, choose a shade that flatters your natural coloring. To highlight blue or green eyes, try a cool, dark color such as slate grey or navy blue. To highlight brown or hazel eyes, try a warm, light color such as maroon or off-white.
Base the formality of your attire on where you'll be going. If you're going to a casual movie, wear a nice pair of jeans and a slightly dressier shirt than you usually would. For an upscale dinner, wear dark slacks with a long-sleeved, button-down shirt; during colder weather, add a well-made sweater on top. Your first date probably won't require you to wear a tuxedo or a suit, but don't show up in the same outfit you'd wear around the house on a weekend morning. Remember: you want your outfit to hit about the same level of formality as what your date will be wearing. If you're unsure, ask your date what the dress code is or what they'll be wearing.