Hold the camera steady.
Now, sure that may sound easy enough, but if you have a slow enough shutter speed, you are still going to experience camera shake despite all the image stabilisation in the world. But there is a method for holding it steady that you can practice and then perfect, every time you take a photo.
In one hand, hold the camera on a 45° angle in the palm of your flat hand. The camera and part of the lens will now be forming a solid base for your camera. Place the other hand around the body in a cupping motion, to provide maximum stability for the camera. Keep your elbows close in to your body as this also steadies the camera dramatically (weird, I know!). If you are looking to buy a camera, practice holding your preferred camera in this manner to check it feels comfortable and that you can easily access all the dials.
Oh! And always look through the eyepiece, not just watching the back of the screen. Your face also provides a stable branch that helps to support your equipment. If all else fails, invest in a Tripod!