Eva went with the 'bright' setting, giving the shot a strong contrasted split light.
Make sure you get in a power stance as you get framed for your photo. Sounds like a joke, but it could really help you stabilize your photo, making it sharper.
The direction and distance of your flash can give your photo different effects, so play with what looks good for your shots.
Holy smokes @evadeitch, great job on this shot! Who knew smoke breaks could turn into portrait breaks. Be sure to check out her feed for more great shots and be sure to tag your #NovaFlash shots on instagram while you're at it.