I get this a lot – When and how many times should I apply moisturizer. There is no one answer to this question. The number of times you should apply moisturizer depends on your skin type. To determine you skin type read my article on finding your skin type. If you have dry skin you need more moisturizer. If you are lucky to have a skin type which retains water without external help (I am not talking about oily skin here) then you need to apply it once a day.
For majority of folks moisturizer needs to be applied twice a day to prevent the skin from drying. The best time to apply moisturizer is immediately after bath when the skin is moist. Moist skin absorbs moisturizer better.
If one has dry skin then moisturizer should be applied as frequently as required – which means as soon as the dry skin feel begins. As a rule people with very dry skin should apply moisturizer every 2-3 hours. For frequent applications oil in water type of moisturizer (or lotion) is better for Indian conditions as it attracts less dirt and does not grease your clothes as much as water in oil type of moisturizer.