SOLUTION
To rectify this problem, all you have to do is find something contrasty or sharply defined to include as part of your subject.

A word of warning: Be careful to aim your focusing spot (usually the center of the digital image) at the main subject you are photographing. Sometimes when shooting a couple the focusing spot might be aimed at the background behind them -- which puts the couple out of focus. 

CAMERA MOVEMENT PROBLEMS
Blurry or soft photographs are usually the result of camera movement and poor focus, but unsteady cameras are the common culprits for blurry photographs -- especially during low light shooting. 

SOLUTIONS
Making the camera stable can be merely a matter of thinking about the existing conditions and how they may effect camera stability. Also, you should hold the camera with your arms pressed against your body and the camera resting on something solid, with both hands holding the camera securely. 

You can also use a wall, chair, or any sturdy object to lean against or support you and your camera.

For timed exposures at night, you can use a shoe, handkerchief filled with sand or dirt, or anything that you can use to rest your camera against to photograph the scene.