Instructions
Update your camera's firmware. Most camera manufacturers have implemented some type of noise reduction software into their firmware package; having the latest version ensures the most up-to-date use of the camera's technology to combat digital camera noise. Updating the firmware varies, depending on the manufacturer.
Use a lower ISO setting. This may be done by decreasing the shutter speed or increasing the f-stop settings, allowing the photographer to use a lower ISO. A lower ISO means decreased sensitivity of the image sensor, and so smaller electrical currents--the cause of ISO related noise--are not recorded.
Use a high-quality lens, if possible, that allows for a wider aperture. This will allow more light to fall on the sensor and allow a decrease in ISO sensitivity, as above.
Use an on- or off-camera flash. Adjusting the lighting will allow the photographer to use a lower ISO. Better lighting equates to a better-quality image where digital photography is concerned.
Use photo-editing software to further smooth and refine the image. Once the image is taken, noise reduction is in the hands of the processing software. Adobe Photoshop has built-in noise reduction found under "Filters" and then "Noise" on the top toolbar. Additional, downloadable software such as Noise Ninja and Neat Image are also noise-reduction packages.