You can add all sorts of flavors or food adornments to iced coffee, provided the addition works well with coffee flavor. Some suggestions for additions to iced coffee include spices like ground cinnamon or chili pepper, syrups such as vanilla or mocha, different kinds of milk like coconut, almond or condensed milks, fresh herbs such as mint leaves or lavender buds, whipped cream with or without sprinkles, coffee ice cubes, and so on. Optional but fun food additions: If you're using a straw, you can thread on mini doughnuts, cookies with center holes or other similar treats for eating with the iced coffee; or just put cookies or cake on a plate and serve with the iced coffee.