I usually start with a handful or two of spinach, 1/2 - 1 cup of milk, a little bit of coconut water (maybe a 1/2 cup) and 3 or 4 big spoonfuls of yogurt. I've tried plain Greek yogurt, but it gave the smoothie too much of a yogurty taste and I didn't like that. I've been using vanilla and it's much better.
I blend all that with the hope that the spinach will become microscopic! (Wow, that looks really gross, but trust me. It's good!)
Today I added a frozen banana, a small handful of frozen blueberries and a few frozen sliced peaches. (Maybe a 1/2 a peach?)
It rarely ever looks that delicious (especially when it's REALLY green), but you can't taste the spinach at all.
I also have a few baggies of frozen fruit in the freezer so I can throw one together without having to get out a bunch of bags.