Improve coffee: Mix some crushed eggshells into ground coffee, to ease the bitter taste, before brewing.
Garden fertilizer: Broken eggshells are a great fertilizer. In addition, they get rid of bugs that destroy your plants.
Facial scrub: Add some egg whites to your ground eggshells. Apply to your face and rinse off once it dries off.
Skin irritation: Pour eggshells into a container of apple cider vinegar and apply it to your irritated skin.
House cleanser: Add some soapy water with ground eggshells and place it at spots that are tough to get rid off, and watch them sparkle and shine.