Give more light
There is an old photographic saying, “if it’s bright, give more light”. Subjects with lots of light tones – snow-covered landscapes, for example – can fool an exposure meter into underexposing. The meter sees all the reflected light and assumes it is a really bright day, rather than a bright subject. If you go with the meter reading, the image will be grey and flat. Giving more exposure than the meter recommends brings the image back to life.
Some compact digital cameras have a ‘snow’ setting on their mode dial. This will automatically give the extra exposure needed. On D-SLRs, exposure compensation of +1 or +2 stops might be required. Check the image on your LCD screen immediately after shooting to see if you need to make an adjustment.