Put the ice cubes and dates in the blender cup. You removed the seeds from the dates, right? Make sure you removed the date seeds. Add the yogurt if using - it will make the smoothie sour, so omit it if you want a more milkshake-like flavor. Add the chia seeds if using. They are a thickener and will improve the texture, and they are also a good source of fiber. You might be able to use oat flour or rolled oats instead. Put in some spices (cinnamon/cardamom/nutmeg). Go easy on them - you can always stir in more after it's blended. Put in the coconut milk and blend thoroughly. Season to taste.