Use gazing direction to balance your portraits ...

DL CADE, 500ISO:

"A balanced composition can make or break a photograph, and when it comes to portraits, one of the easiest ways to balance a composition is to take advantage of gazing direction.

...

"When you compose a portrait according to the rule of thirds or golden mean, your composition will naturally be weighted to one side or another by your subject. Here’s the tip: Once your basic framing is set, try having your subject look out of the frame in the direction of all that ‘empty’ space to their right or left."

Read more, here.