If the feeders are near a window, alter the appearance of the glass to help reduce window collisions. Try covering windows with a fine plastic garden netting, placing hawk silhouettes about four inches apart on the outside of the window, or painting a scene on the window's exterior with soap. Many birds will feed at more than one level, but they do have their preferences. Selecting a feeder - Plastic, steel, or glass feeders are best because they are easy to clean. Feeders with porous surfaces, such as wood or clay, can be difficult to clean and may grow dangerous algae and fungi.
Smaller feeders empty out more quickly, so there's less chance of wet, spoiled seeds.
Rain can be a problem, so make sure the feeder has drainage holes, and consider placing a plastic dome on top. Set up more than one feeder and allow ample space between feeders. Choose feeders that have no sharp edges or points. To help keep food cleaner, use feeders that allow birds to perch away from the food. Clean feeders often.