Big fruits like oranges, should be cut in half. Impale the halves on a stick or limb, or use a nail to attach the fruit to a tree, fence post, feeder, or even a deck. You may want to try chopping up bits of fruit and scattering them on the ground. A shallow bowl is a good choice for providing bits of fruit. You will probably want to separate the fruit from your seed, as the fruit can get messy.
Dry fruits are great for convenience, and less messy.
You can get them in the health food store, or even dry them yourself in the oven at a low temperature 4-12 hrs. Wild fruits can be dried and saved to use later when food is more scarce. When offering the fruit, put it in the same place every time. It may take a while for the birds to discover it. Be patient, once they find it, they'll return again and again.