There are five basic elements to everything that exists... earth, water, fire, air and space.
Earth is the solidity, substance and weight.
Water is the fluidity, moisture and flow.
Fire is the ignition, driving-force and transformer.
Air is the movement, lightness and instigator.
Space is the vacant-ness, open-ness, and nothing-ness that allows everything to be.
Everything is made up of varying proportions of these fundamental elements, including ourselves.
When you know the various attributes of each element, it is possible to maintain balance within yourself by simply increasing or decreasing any of the elements... just like cooking without a recipe book... too dry, add some moisture; too wet, add some dryness; too heavy, add some lightness; too cold, add some heat; too dull, add some spark etc etc
These basic principles can be applied to every aspect of your life... the food you eat, what you do, the environment you're in... in order to maintain balance and well-being.