Humans are mundane, non-magical, having no natural magical abilities. In order to effect magic, they must have substances which are embued with magical energy. By harnessing the power of these magical ingredients, humans can "do magic".
Different magical ingredients have different magical properties and different power levels. Dragon tonsils, for example, are known to be highly charged with magical energy related to the dragon's breath weapon. Magicians have found, for example, that Red Dragon tonsils make the best base ingredient for fire-related spells, while Blue Dragon tonsils are ideal for electricity-related magic.
Wizards have found various techniques for the storage of these magical ingredients.
One of the most basic methods is incorporating the magical substance into a liquid potion. The potion can be drunk to internalize its magical power, although this method can be dangerous and lead to unpredictable results. The potion can also be poured out, dispersing its magical effect upon whatever it is poured upon.
Through the process of distilation of liquid potitions, magical powders can be created. On the plus side, powders are more concentrated than potions, but on the downside, they are more volatile. Magical powder is the base ingredient for most types of dynamic, on-demand, spell casting. Powders are also appropriate for distributing magical effect carefully and evenly over specific areas. Warning: Sprinkling magic dust on intelligent creatures can lead to highly unpredictable results!
Wands, Staffs, and Rods
The most primitive wands began as pieces of wood which were soaked in magical liquid. The wood asborbed the magical properties of the liquid, and magicians learned to channel the magical power, usually with magical power words. Superior wands are made of wood from magical trees, as they have proven to absorb and store much greater magical power. Experiments are also being conducted with hollow-core wands, which allow magic power objects to be contained within them, greatly amplifying their magical powers. Rods and especially staffs are particularly useful for that purpose, as they are larger and more easily cored. The techniques of wand making continue to be advanced.
Scrolls are best used for channeling the power of magic power words. The fiber of the scroll is embedded with magical power at its creation, using magical plants, liquids, and powders in the process of crafting the paper. The magical power word or phrase, usually stolen from one of the intelligent magical races, is then enscribed on the scroll itself, with magical ink if possible. A tremendous amount of magical energy can be stored in this way.
Cloaks, boots, gloves, hats, and so on, are usually created from the skins of magical creatures. Fire Giant skins have proven to provide excellent fire resistance magic, for example. Another popular method of creating magical clothing is by soaking natural fiber clothes in the blood of magical creatures.
Metal Items - rings, weapons, etc.
Items made of precious metals are excellent at absorbing magical energy directly, storing the energy like a battery. Wizards have found that metals can direcly absorb spell power cast at them, storing it for later use. Metal items can also be charged up with magical power, when placed in a location where such magical power naturally accumulates. Locating such natural "magical vortex" areas is a cherished goal for many in the magic using community.