To make a yogurt or kefir smoothie, put some kefir or yogurt in a blender.  Add fresh or frozen fruit or berries.  Add a sweetner (if desired).  Blend until smooth.  Serve in a pretty glass with a straw.

Add some ice chips
Add an egg or two for more protein
Add several types of fruit...strawberry and bannana!
Add a spoonful of ground flax seed