Use water (or almond or coconut milk) as your base
Spinach (hefty handful)
Strawberries (1 cup)
Cherries (1/2 cup)
¼ avocado (for some good fat and extra creaminess)
1-2 tbsp of flaxseed or hemp seeds (Omega 3 fats!)
Add ice and blend!
Bonus – make ice cubes from vanilla almond (or coconut) milk