The soil quality plays a crucial role in civil engineering, affecting the safety, durability, and stability of constructed structures. This paper explores advanced soil improvement techniques in civil engineering applications, such as foundations, road construction, and slope stabilization. Both traditional and cutting-edge methods are examined, including soil stabilization with chemicals, the use of geosynthetics, and biotechnological approaches. Additionally, this paper evaluates these techniques' environmental and economic impacts, providing a holistic view of soil enhancement practices in modern engineering.