Used coffee grounds are versatile for both indoor and outdoor use. Let the grounds dry out and then place them in a cup or bowl on the counter or in the refrigerator; coffee grounds are a natural odor absorber and help keep the home smelling fresh. Likewise, scrubbing hands with coffee grounds helps eliminate the smell of onions or garlic while a person is cooking.
Sprinkling coffee grounds around doors helps keep ants away as the nitrogen in the used grounds burns ants' feet. Another indoor use for coffee grounds is as a natural conditioner to make hair shiny and smooth. This helps highlight dark hair naturally.
Coffee grounds are a benefit in outdoor flower beds as well. Used grounds can be dumped straight into the plants to provide enriching nitrogen for the soil. New seeds also benefit from used coffee grounds. Dry out the grounds and mix them with the soil when planting seeds. The plants grow in thicker than they do with plain soil. For those who have a problem with cats in their gardens, coffee grounds and orange peels help deter the cats in addition to enriching the soil. Keeping cats away from the garden benefits them as well, since many plants are not safe for cat consumption.