Some basics for a smoothie are:
A blender: I have a cheapo one. I regret buying the cheapo one, and wish I would have purchased one that was a bit more sturdy, but it works.
Some greens: This is an easy way to add greens to your diet. You don't taste them, but they still pack a great nutritional wallop. I use the really nutrient dense ones, such as kale or spinach. You can use a lot. I add 2 handfuls.
Frozen berries: maybe a cup. This replaces any ice cubes you may otherwise have used and adds antioxidants and yumminess.
A dairy base: milk, kefir, Homemade Yogurt. Some folks enjoy using almond or coconut milk. That works as well, but I usually use milk and yogurt. These ingredients are cheap, plentiful and local. I used milk and yogurt, but use what makes you happiest.
Banana: I use one banana to give my smoothie a creamy consistency and sweetness. I probably could have gone without this, as the yogurt already gives the drink a nice texture.
Finally, I add one tablespoon of black strap molasses. This stuff packs a mineral punch, adds sweetness and a deeper flavor. The molasses has calcium, iron and other trace minerals.
Now, blend it, pour,
This is a base that can be changed. Remove the berries, the banana and molasses and add frozen peaches, vanilla, cinnamon and maple syrup. This is a great healthy treat that you can have as a snack or meal. YUM!!