Come summertime, when I'm getting all those tomatoes, the gazpacho is my favorite "smoothie", with the tomatoes, bell or other mild peppers (I'll add some heat sometimes, but usually leave it mild, in case I have visitors), cucumbers, a small shallot, a clove of garlic, some olive oil, and some sherry vinegar. And something that I add to this, to keep the water from separating, is some chia seeds, or a small amount of xantham gum. For fruit smoothies, I frequently use those very ripe bananas, some pineapple cubes, maybe some other fruits I have around - apples, oranges, or tangerines - and a little yogurt, blend it briefly with a tb of chia seeds, then let them sit 5 min or so and gel. Then blend on high, and I usually remove about half and refrigerate that, for a later use, and add ice to what's left, and blend until smooth. I often add a few drops of coconut flavor to these, as this is delicious with the banana and pineapple.