First take a lot of photos, professionals say that there is one great photo in every 30 taken. Second, consider the lighting, indoor lighting may cast a yellowing effect. Outdoor photos are best, but indoor during the day time near a window may also be good. Third, look at the angle you are taking them from. Often we grab the camera when they are being cute and shoot downward. Plan your photo shoot, play with them, give treats, that gives them relaxed faces and then get down on their level, make noises that make them alert, ears up is always cute. Try zooming in and filling the frame or minimizing the amount of background. Hopefully you will find some inspiration here.