I make smoothies nearly every morning, all but one day a week! They are great because you can do most anything.
Fresh fruit is the first thing in it. Then, I generally use plain yogurt too

. From there, the sky's the limit.
Here are some good things to add.
1. Chia seeds. High in protein and will keep your blood sugars level. Very important if you're trying to lose weight.
2. Wheat grass powder. Good way to get greens in.
3. Flax seed oil.
4. Whey. A small amount could be used in place of yogurt.
5. Nuts and/or seeds.
6. Goji berries.
7. Bee pollen.
8. Raisins or dried apricots, softened in water for an hour or overnight. Make sure there is no sulphur in your dried fruits.
9. Shredded unsweetened coconut.
10. Peanut butter or almond butter.
11. Pomegranate juice.
If you absolutely must sweeten it, though you shouldn't since fruit is naturally sweet, use raw honey. Splenda has chlorine in it. It's marketed as a health product but far from it. To keep it simple, look at the things God has made. Keep it simple. If man has tampered with it, you're getting into trouble. The more something is processed the worse it is for you.
Some good combinations are
apple and strawberries
pineapple and pear (with a dash of cinnamon, with helps to metabolize fat)
a few grapes with any fruit will sweeten it more, as with banana
papaya, apple, and banana
Throw 1/4 cup of blueberries in any smoothie to increase your antioxidants big time. In fact, have 1/4 cup of blueberries every day.
These fruits are the ones to use sparingly if you are trying to lose weight.
Banana
Mango
Papaya
Pineapple
Smoothies are good by themselves, or with granola or cereal sprinkled over them. Try mixing it with cottage cheese.
Have fun!

And I wish you success at losing weight. Remember, you didn't put it on overnight, so don't try to take it off overnight. Just eat right, and exercise. It will happen.