While there are times when having nothing but your subject in your frame makes for extremely powerful pictures, you can add depth and meaning to your portraits by drawing on one additional element - Context.
In the example above, you see only the subject, and that too just partially. This is great if you're simply looking to bring out detail and nothing else.
But this composition doesn't give a sense of the setting - you're not really capturing the 'where' of this moment.
Showing more of your subject plus revealing additional location-details starts to 'place' your photograph better, as you see below.
And as you move around your subject, using a combination of wide-angle lenses (24-70mm or 16-35mm) and high/low framing, you can start seeing different foreground and background elements that can come into play, to support your picture.
By choosing the most relevant foreground and background elements, you can then create the best context in your pictures.
Happy Photographing!