Leave the bag of strawberries out at room temperature for a little while until they are a bit softer.
Add ingredients to blender, soymilk on the bottom and banana 2nd. Depending on your blender's capacity and strength you might have to chop the strawberries. If you use unsweetened soymilk then you can make this smoothie without any refined sugars. This is what I do and it is wonderful and sweet without it.
Use any flavors of juice concentrate you like. I keep 2 flavors of 100% juice concentrate in my fridge just for this purpose: apple-strawberry-kiwi and orange with calcium added. This could easily be replaced by maple syrup, agave, whatever sweetener you choose.
Some people don't like flax, but it isn't even noticeable and is a great way to get added nutrition, so I suggest using it.
The recipe yields 4 cups.