Cut banana up into pieces into blender, or I have one of those smoothie machines. Add yogurt. I use whatever yogurt is on sale that week, but usually use Yoplait or the Store brand.
Add frozen fruit (using frozen so don't have to add ice and water it down), I like to use mixed kinds to get different flavors. Use whatever kinds of fruits you like. It might take a few tries to get what you like.
Add juice. I usually use orange juice or the orange/peach/mango flavored variety. Or I look in the Mexican food aisle and buy Guava and Peach nectar for a different kick. I like this a lot better than those smoothies with milk or ice cream and think it's healthier too!
After blending and if it's too clumpy and thick add 2 or 3 more splashes of juice and blend some more till the consistency you want.