Incorporate folds into your anime character's clothes to reflect motion from gravity, wind or tension (a sleeve being lifted by an arm, for example). Downward lines are effective for gravity, while horizontal or sweeping diagonal lines best portray wind and tension.
Draw shirts with sleeves that stretch toward the shoulder area. Place horizontal or diagonal lines reaching across the natural gathers of the fabric, such as at the waist and armpits. Even loose-fitting clothes will have gathers around these areas.
Draw an extra rim on a collar or bell of a sleeve to denote thick, heavy fabric. A thinner border will make your fabric look light and airy. You can easily apply these techniques to pant hems, skirt hems, shirt pleats and scarves as well.
Drape fabric loosely over larger figures, such as priests, monks and angels. The pleats of these clothes should be drawn with vertical lines, as if gravity is pulling them down.
Draw pants or skirts with close attention paid to the backside and waistline. These areas are where you will accentuate the natural shape of your anime character, keeping in mind that even loose fabric typically bunches near the beltline. Avoid too many folds here, unless you are trying to achieve a martial arts or creative look.
Add tight-fitting clothes to action figures, with no wrinkles, pleats or folds. These clothes should be bright in color (primary colors) and can feature accompanying weapons, such as swords or knives.
Shade the areas of your character's clothes that are not exposed to light, such as grooves, the inside areas of folds and places where the fabric gathers.
Create a unique look with stripes across your clothing. Be sure to draw the movement of the stripes, particularly across sleeves and skirts, by breaking the stripes into natural horizontal sections across folds.