The dress you pick needs to fill many requirements and the more choices

The dress you pick needs to fill many requirements and the more choices that you have means the more chance you have of finding just the right one, the right color and the right style, once you have the right dress for your coloring, size, shape and your accessories the only thing that can make you stand out now will be your dancing.
Each part of what you will wear has an effect on the rest of what you will wear, if you are wearing a dress of a dark color then you may want light accessories, silver or glass type of jewelry to enhance your look rather than something that is dark that will just blend making one large color. Shoes should also be matched to the dress, a long dress usually will look better with a shoe with a heel on it, rather than a flat shoe, but this does not mean a heel that is extra high as this will not give you much comfort for the evening.
Rather than a dress that is low cut, you can opt for a dress that has beads or sequins as an adornment to show off your dress, accessories can also help to make the look of the dress one to remember, beauty is not always skin.
Color is also important to make your dress perfect for you, the wrong color can make your skin appear washed out, it can make your face and your hairstyle appear non-existent. So, color is very important, to bring out your features.
There are items called color wheels that will tell you what colors are for your type of skin color, for makeup and there are also ones for dresses. This is an important night and you want to be noticed for the right reasons, not blend in, and not be noticed for the wrong reasons. You have decisions to make and they should not be stressful, but you should consider them carefully to make the right choice in your dress.
Do you have nice shoulders that you would look nice in a dress with thin straps or no straps? Will you wear your hair up and want to show your neck off because it is a good feature, then a dress that shows off your neck might be right. Is there a certain color that when you wear it everyone tells you how nice you look? These are things that you might consider when you are picking out your prom dress.
If you are not sure about color you can get color swatches and check them against your skin and hair to decide if a color will look right on you.