My top three uses for Food Grade Diatomaceous Earth:
1. The War on Fleas
Since we live in Maine, we don't normally have too much of a problem with fleas. But every few years, we'll have a hot, dry summer and I'll start finding fleas around. Whenever you are dealing with fleas, it's great to take a multi-point approach in your plan of attack. I'd never win the war on fleas without food grade DE. I dust my dogs and cat with the powder, and also sprinkle it on any carpets, dog beds, blankets, and couches (any soft surface where fleas may leave their eggs to hatch).
2. Internal Parasites
Feeding your animals (and yourself) food grade DE can help eliminate many types of worms. For more information on dosing and which types of worms will be eliminated, see this article: Diatomaceous Earth for Pets.
3. Face Mask
Mix food grade DE with water to make a beautiful face mask (for humans). Let dry for about 5 minutes and then wash off. It's gentle, purifying, and not too drying. I follow this up with some coconut oil to moisturize.
In addition, you can use DE to polish your kitchen and bathroom fixtures, as it makes a great cleaning paste. In many ways, it can serve the same purpose as baking soda, since it also deodorizes and absorbs moisture. You can also add it to your toothpaste! Here's a great article that goes more in depth on the many ways to use DE: 15 Uses For Diatomaceous Earth.