Secret number 1: You can freeze baby spinach leaves. You do not want to buy prefrozen spinach (trust me. It's icky!) but if you purchase the large bag of fresh baby spinach from the produce section you can freeze what you don't use. The leaves freeze individually making it a cinch to scoop up what you need to use each time you make your smoothie. Our local grocery store regularly marks the spinach 50 - 75% off regular price up to FIVE days before it expires. When I see that I pick up a couple to keep in our freezer.
Secret number 2: You can buy cans of coconut milk at Asian grocery stores for a lot less than regular grocery stores. In fact I was told they'd cut me an even better deal if I were to buy an entire case of 24 - so it wouldn't hurt to ask if you could get a better deal at your store too!
Secret number 3: The Dollar Tree carries frozen fruit. I was so surprised when I saw it in their frozen section. I picked up a few bags of peaches, blueberries and strawberries - they are between 12 and 16 ounces each which is cheap for frozen fruit. And there is nothing added to it -it's pure fruit. Having used it for the last 3 weeks I can honestly say it tastes just like more expensive frozen fruit. If you're local Dollar Tree has a frozen section check it out for their frozen fruit!