It can take several days for birds to notice the feeder. Keep the feeders clean and dry. Replace the seed if it becomes wet since birds won't be attracted to moldy seed. A yard filled with bird-friendly native plants will also help attract birds.
A poorly placed feeder is unlikely to attract birds. Move the feeder if it is in the open. A sheltered location within 10 to 15 feet of trees and shrubs is better than in the center of a lawn. Don't place the feeder any closer to trees or any items that cats and other predators can use to launch themselves into the feeder. Feeders should be placed in a sheltered location out of the wind.
The birds may be ignoring the feeder because they are getting their fill of natural food. Numbers at feeders tend to be lower in the summer, fall, and early winter. Mild winters with little snow cover can also reduce visits to a bird feeder.
The birds may be rejecting your choice of birdseed. Choose single seeds or make your own mixtures based on what birds you want to attract. Black-oil sunflower is always a good choice that attracts a wide variety of wild birds, especially chickadees, nuthatches, and titmice. White prove millet will attract doves, juncos, towhee, and sparrows. Avoid seed mixes that contain milo and red proso millet, which few birds favor.