Add 1 cup orange juice, 1 cup plain yoghurt, 2 to 3 tablespoons honey, 1 1/2 cups fresh or frozen blackberries and 1/2 cup frozen unsweetened mixed berries to a blender. Use the lid to cover the blender and run it at medium speed for about 15 seconds. Check to see if the mixture in the blender is smooth. If it is not, you will have to blend until the yoghurt or blackberry lumps completely vanish from the mixture and all you see is plain liquid. The blending time will be considerably longer if you are using frozen blackberries instead of fresh blackberries.
Pour the drink directly into some chilled glasses and be sure to serve immediately. This is important because the longer you wait before serving the higher the chances of the original flavour of the drink turning bad.
You can add or subtract any ingredient according to your own specific taste. If you want, you can also add some different fruit to the smoothie recipe to give it a unique flavour.
To make the drink look delicious, consider topping it with additional blackberries and yoghurt. However, this is not necessary and you can enjoy Blackberry Smoothies without any topping as well.