The best tip for capturing motion blur is to select a longer or slower shutter speed. The slower your subject, the slower the shutter speed needs to be to create blur. This will cause your camera’s shutter to remain open for a longer period creating a blurred effect as camera shake will occur along with the natural movement of the subject. However, a longer shutter speed lets more light into your camera and runs the risk of overexposing your image.
In contrast, shorter/faster shutter speeds will freeze the action producing sharper images. 1/250th of a second and below should be fast enough for recreational sports, skaters, etc. However, you’ll need to go a lot faster if you want to capture a baseball in mid-flight or other pro-sports. You can also pan your camera to get the effect of fast movement. Another tip for taking sharp motion pictures is to have a wide aperture (f/3.5 or lower) which will create a narrow depth-of-field and help the subject/subjects stand out.