How can I achieve this look?
First thing is to slow down your shutter speed. When your shutter is open longer, the person has more time to create a blur of motion. Your aperture can be at a mid to lowish number. Remember by lowering both of these numbers, you are letting lots of light into the camera, so bump your aperture up a smidge to compensate for a lower shutter speed such as (60-80th of a second), your aperture may be somewhere around 2.8, 4 or 5.6, depending on your light and lens. But these are rough numbers to start.
If you are confused by shooting manually, try "shutter speed priority" mode on your camera and the same scenario should occur, give or take a little.
Next frame your shot and have your subject walk back and forth in and out of the frame a few times. Try having them carry something or just walking; just be sure to give yourself options and don't forget to direct your subject to achieve what YOU need as the photographer. Most people are happy to oblige.
Leela the Photo Magician
(Image: Adrienne Breaux for Apartment Therapy)