Use Frozen Fruit
The recipes don't always specify, but if you have time to freeze your fruit beforehand, your smoothie will stay colder and be thicker than if your fruit was warm. Large fruits (like bananas or melons) should be chopped into pieces before freezing. Spread the pieces on a plate or baking sheet while in the freezer. That way they won't freeze into one big lump. Once frozen, then you can store them together in a freezer bag or container.
To Keep it Healthy
There are lots of small substitutions you can make to lower the fat content of your smoothies. Use skim or soy milk instead of regular milk, or frozen yogurt instead of ice cream. Add nutrition with some wheat germ, protein powder, or brewer's yeast.
Not Thick Enough?
If your smoothies are coming out thinner than you'd like, add a few more ice cubes to the recipe.
Make Ahead Smoothies
To grab a smoothie on the go, make them up ahead of time. You can freeze a smoothie and thaw it out when you want it. You'll need to allow some space in the container because your smoothie will likely expand when freezing.
Add the liquids to the blender first, to prevent it from binding up on the frozen fruit and getting stuck.