Be sure to use fresh food and keep feeders clean. Moldy or infested food is neither appealing nor healthy.
      
            Place feeders at least 4-5 feet above ground height to discourage predators. Either right next to a window or very far away from it will minimize the chances of a bird flying into a window.
         After putting up a feeder, it may be months before you have a visitor; it sometimes takes that long for birds to find and feel secure about using a feeder. There may also be long times in the summer when the feeder is not used because birds have other sources of food .
 

      Hummingbird nectar need not be red. A red feeder or a red ribbon tied around the feeder will do. A dilute solution (5:1 water to sugar) is sufficient. A weaker solution is fine but a stronger solution may cause sugar crystals to form on a bird's bill, creating the potential for bacterial infection.
                   Feed regularly. Although birds can usually find other sources of food, they are more likely to visit your feeder regularly if the feeder is usually full. See Hummingbirds.net
  
                  Bird predators such as Sharp-shinned Hawks may visit the feeder and prey upon the other birds. Research has shown that the survival rate of birds who have an accessory source of food from a bird feeder is greater than those who do not have such access even though the predation rate is higher. In other words, starvation is a greater risk than predation.
Finally, there is no magic menu; different seeds and different mixtures of seeds attract different birds. Below are links with lots more information.