So what makes a great senior portrait? This is one of those questions that could have many different answers, it all depends upon who you ask.
Back when I was a high school senior (many years ago) your typical senior portrait was Guys - suit, white shirt, tie; Girls formal dress or drape. Now days very few seniors want this type of image. We still do it from time to time, but it is almost always because the parents want it.
Now days most seniors want images tha reflect who they are. I personally feel these types of images do make the best senior portraits. They show who you are and what is important to you.
You can do this in a variety of ways.
You can use images that portray things you are interested in:
You can shoot in clothing or locations that you like:
You can go for a fashion/model look
Or something more "artsy"
No matter what style, or styles you choose, you should have fun when you are shooting your portraits.