If using a fresh orange, grate the zest with the medium to fine holes on a grater. Cut the orange in half and juice, using a hand juicer or simply squeezing by hand.* Pour 1/2 cup juice into blender.
Juice lemon (or lime) and scoop out the flesh of the avocado, then add to blender.
Add all remaining ingredients and blend until smooth. Adjust seasonings, to taste.