Do you use lemon or orange zest in recipes? If so then make your own! You will need a handy dandy Zester Tool to do this.
If you buy organic oranges or lemons, before you juice or cut them up, ZEST them!
Also after zesting you really only have the pith left that contains all that extra Vitamin C. So all you need to do is cut up and throw into your smoothies, if you make smoothies. Warning the pith will make your smoothie a little more tart!
I store fresh zest in a quart size container in my freezer. When it is full I dehydrate the batch and store in a sealed mason jar.