These can be offered on a platform feeder or in a suet feeder. Suet that has fruit or insects in it is good to attract orioles. You also may want to try grape preserves or orange marmalade. You will need to replace these fruits and preserves daily to keep them as fresh as possible. There are nectar feeders for orioles that are very similar to hummingbird feeders.
Hummingbird feeders are usually red, and oriole feeders are orange and have larger feeding holes.
Nectar for oriole feeders can be purchased, or you can make your own. This is done by boiling together one part sugar to six parts water. Let the mixture cool before putting it in the feeder, and store any leftovers in the refrigerator. The nectar will need to be changed every four to five days, and the feeder should be washed in hot soapy water. You may want to consider planting certain trees and bushes, and you can offer nesting materials to attract orioles.