A few notes on the smoothie making process...
If you have a less powerful blender you might try cutting the oranges into smaller chunks. Or, you can exchange them for a different fruit.
Another blender tip. Try using milk (dairy, almond, coconut, hemp, hazelnut, sesame, what ever is your favorite or you are adventurous enough to try) along with or instead of yogurt. It sometimes helps to put the liquid ingredients in with the spinach first, in my experience, and get that chopped up and in a puree form. Then adding the fruits.
Using fresh fruits is wonderful however frozen works great to.
Experimenting with a recipe by changing things up can add variety of taste and nutrients.
I have added Kale and other greens to a smoothie and have been amazed at how it doesn't overpower the sweetness and good taste
From the Two Peas and Their Pod blog
Green Smoothie "The Green Goblin"
1/2 of a large banana, cut into chunks
6 large strawberries
2 cups spinach
1/3 cup plain Greek yogurt (I use Chobani 0%)
1 cup ice
Note-I use our Blendtec Blender which is a very powerful machine. Make sure you use a powerful blender that will puree the orange, spinach, ice, etc. I like to store one serving of the smoothie in the freezer for later. Pour in an air-tight container and freeze. Make sure you take the smoothie out of the freezer about 30 minutes before you want to drink it. You can also store the smoothie in the refrigerator.