In a container, combine the drops and water by putting the drops of peppermint spirits into your container first, then add the water. This mixes it well without having to shake it a bunch.
Note: This is what Peppermint Spirits (by Herb Pharm) looks like. I get mine at Whole Foods, but this is a brand that many, many health food stores carry. Call around and ask to see who carries it in your area. If the store carries the brand but not this particular extract, you can easily have them order it for you. It's not cheap, but when you use it a drop at a time, it lasts for several months. Also note that not all peppermint extracts are created equal. If you buy the stuff they sell in the baking isle at your local grocery, you will be very disappointed in the result. I don't normally do product specific recipes, but this one is worth it. Trust me!
Please note that the nutrition data given here is a ballpark figure. Exact data is not possible.