Just be patient. Keep the feeder clean and full of fresh nectar (4 parts water to one part sugar) and hang the feeder in a place where you can see them, but make sure it's near trees but away from places potential predators can get to them.
Hummers will also love your feeder if you have it near bushes or flowers that bloom; like berry bushes that blossom or your window box full of blooming perennials. This attracts them because they see the opportunity for more than one food source.
But like I said, be patient; especially if there's a lot of human traffic going past the feeder throughout the day; they need to take time to get used to the new feeder and your presence.