Sundews prefer full to part sun or bright artificial light. Most species of sundew require at least six hours of direct, high intensity light to thrive. If your sundew is not producing dew it most likely needs more light. More info on lighting may be found here (Link).
Most sundews thrive on the tray method, which keeps the soil permanently wet. A few prefer to be waterlogged, you may need to do some research on the individual type you intend to grow. Use only mineral free water, more info on water is available on this page (Link).
Temperature and Dormancy:
As sundews grow across the globe, they come from varied climates. Temperate sundews require cold winters see the dormancy instructions for Sarracenia. Warm-temperate and sub-tropical sundews do well on windowsills, in cool greenhouses, or terrariums and appreciate cool nights. Winter growing sundews from Australia and South Africa could be grown outdoors in a Mediterranean climate without frost or in a cool greenhouse.
Winter growing species require periods of complete summer dormancy, at which time the soil has to be dried out. As summer approaches wait for the plant to quickly go brown. Then reduce watering so that it slowly goes dry over the course of a month. Keep in a cool, dry place during summer dormancy and sprinkle them with water once every couple of weeks.
Information regarding soil can be found on my soil pager here (Link).