Instructions
Select a lower shutter speed. The lower shutter speed will let in more light, which is necessary when less light is available. For a bright cloudy day, use a 1/500 second shutter speed; a highly overcast day might need a 1/125 second shutter speed.
Adjust the aperture size. The lower the F-stop number, the larger the aperture opening and the more light is let in. Try F 5.6 on a more overcast day to let more light in.
Use a tripod. Lower shutter speeds cause the photo to be more affected by movement, as it takes longer to shoot the picture. A tripod will eliminate blur caused by hand movement. Use the camera's remote to take the photo if you have one.
Tweak the settings. Choose a cloudy day and play with the shutter and aperture combinations to find the one that gives the best results. Then when a photo opportunity comes along you will be ready with the correct adjustments and won't miss the shot.