Fresh fruit like pineapple, apples, and oranges. Try 1/2 cup first to see if you like it. Add in before or after cooking.
Orange zest, zest of one orange or about 2 tsp. Add in before cooking.
Orange juice, substitute half the water for orange juice.
Orange liqueur like Grand Marnier, add a tablespoon at the beginning of cooking.
Nuts, add in 1/2 cup pecans, walnuts, hazelnuts, etc. Add in toasted nuts after cooking.
Dried fruits, chopped-up dates, figs, raisins, cranberries, cherries, and apricots will add texture and flavor. Add at the beginning of cooking.
Spices, add in a dash of nutmeg, cardamom, and cinnamon to taste before cooking.