Drinking lots of water is the easiest way to look fresh even after long hours at work. Dehydration is the main cause why your skin looks old and tired so try to drink as much liquid as you can to look young and vibrant. Nutritionists recommend up to 8 glasses of water a day so try drink that much. Though you should avoid coffee and tea, however, because they’ll only make you urinate more frequently and every time you urinate, your body losses more water and ends up even more dehydrated.