The choice of pants depends on the style of the shirt and the occasion. For a business shirt, it's best to opt for matching suit pants in a classic color like gray, navy or black. Chino pants or wool pants can also be paired with a business shirt for a professional look. For a more casual look, denim pants can be worn with a casual shirt. In general, it's advisable to choose pants that complement the shirt in terms of style and color, creating a harmonious ensemble.