Bath bombs are a lot of fun to make and the main ingredients used to make it fizz are common baking soda and citric acid. Additional ingredients can be added to make them more moisturising for your skin. A special kind is the bubble bar, which add bubbles to your bath water. Check out the basic bath bomb tutorial to get started.
Body scrubs are exfoliating and rely on both mechanical exfoliation (salt, flours, clays, pumice, etc) and chemical exfoliation (sugar and fruits), the latter loosens the glue holding the dead skin cells together and the former literally scrubs them off. Regular exfoliation results in healthy skin, because it helps boost circulation and encourages cell renewal, and it also leaves your skin looking fresh and glowing!