Fire is the element of Strength, Destruction, Charisma, Passion, and Heat in Seirei no Kuni.
Fire is associated with living land creatures, plants that thrive after fires, fire itself, blood, and others.

This element is used most often in potions to increase passions (typically as a cure for martial troubles), in wash rags to get dirt and grime off of pots and pans and other utensils and dinnerware, to artificially keep things hot in the form of fire imbued rocks, and applied to tools to make them more efficient at their jobs such as tilling fields or cutting trees.

Water is the element of Dexterity, Life, Wisdom, Balance and Cold.
Water is associated with water, sea creatures, things exclusively found around water such as seashells, and other liquids.

This element is used most often as a way of preserving food, as a box imbued with the element tends to keep things unnaturally cold, in potions to help in a difficult decision, added to weapons to give them an unnaturally perfect balance, imbued into tools to ensure a greater harvest (in this case such as imbuing a fish net with water is more likely to gain the wielder a greater haul, as water attracts life and such), and into planters boxes to help small gardens grow much more robust fruits and vegetables as well as other herbs.

Earth is the element of Durability, Creation, Rationality, Stability, and Bluntness.
Earth is associated with dirt, grass, metal, stone, and the remains of dead animals in the form of things such as leather or bone.

This element is used most often in the building of homes to increase their durability and stability. Earth potions or talismans are used by artists most often to help inspire their creative juices in conjunction with wind. Earth is also usually used in sheathes for dangerous weapons in order to keep them slightly less dangerous outside of the intended situations. Earth charms are used in households in order to keep a relationship more stable, and most wedding bands are imbued with earth for this reason in conjunction with fire to ensure a passionate, but stable, marriage. Tools imbued with the earth element last for almost ten times as long as their non-imbued counterparts.

Wind is the element of Speed, Nothingness, Impulse, Dreams, and Sharpness.
Wind is associated with the air, and winged creatures.

This element is used most often in conjunction with other elements as it does not give many benefits on its own. Wind can be used to imbue speed onto objects, making one move slightly faster, or jump higher for instance. Wind is most commonly used to keep knives and other bladed tools sharp beyond what can be naturally made. Wind is also used in conjunction with the other elements for its impulse or dreams facets, typically with earth as a grounding agent or water.