How should I do my prom makeup?
My dress is turquoise with a tan lace over it.
I have black hair, brown eyes, and yellow undertones. My skin is rather tan.
Please provide suggestions for eyes, blush, and lips. 
This is what I did for every prom ive been to and always got compliments. For the mascara, of course get it in black and where its going to stand out. I would use browns the match the small detail in your dress and maybe just at the corner of the eyes a turquoise. I dont buy the whole dont match the shadow to your dress, you cant wear purple eyeshadow then have a blue dress. Eyeliner, just becasue its prom doesnt mean you have to have a ton on. Get a blue kind of liner. It always looks really cool. Use blush not bronzer, i think bronzer is to basic for prom but buy a blush that you think you will use again. Same thing with your lip product. I personally like the lips with color in it. A nice light pink is always good. A definate suggestion is Victoria secrets lip plumper in baby pink. Its such a nice color. Just have fun with your makeup, wear colors on the eyes you wouldn't normally wear. You might surprise yourself and love it. Prom sucks when its over, I just had my last one last year and i miss it like crazy. Have fun.