I've never had much luck making smoothies until I threw this one together. It is ridiculously good for you, amazingly delicious, and super easy to make! However, my favorite thing about it is that you can store some in the fridge and it stays smoothie consistency for at least 24 hours (maybe longer, I haven't tried yet)! For the frozen strawberries and bananas, I freeze my own from fresh. I imagine the frozen kind you get from the store would work well too. You could try substituting other fruits or juices, but I can only guarantee the results with this recipe!