Wife often uses 4oz of blueberry juice or cranberry juice with approx 1 to 1 1/2 cups frozen fruit mix (dark cherries, strawberries, and mangoes), with a scoop and a half of vanilla whey protein.
I like to use the following as it taste like a cream sickle: I'll juice approx 150g organic carrots, 1 large red delicious apple (skinned and cored), and half of a lemon, with one to two scoops of vanilla whey protein. Needs to be a good protein powder, one that blends down easy, smooth, and of course has a good taste. The apple will sweeten the drink a lot, so don't worry about the carrot taste. Also can do the full lemon, sometimes I do. Lastly I'll add approx half a cup or so of strawberries, but when you do that you lose the cream sickle taste.
Those are just two of the ones we've used in our house. On a quick side note (don't feel like going to kitchen to find the exact amounts...it's written down somewhere), cauliflower and strawberries with a vanilla based protein taste pretty good as well (think we put a bit of lemon in as well), can't remember the exact ingredients been a while.