In this paper, we provide a practical solution to the generalized optimal guidance problem with an impact angle constraint. The optimal guidance problem with arbitrary weighting functions is extended to explicitly consider a missile dynamic lag effect as well as a missile velocity variation. Therefore, compared to existing results, the proposed result can prevent performance degradation due to the dynamic lag effect and the velocity variation, which is an essential issue in practice. Besides, since the proposed guidance law is formulated from the generalized optimal control framework, it can directly inherit a vital feature of the framework: providing an additional degree of freedom in shaping a guidance command for achieving a specific guidance operational goal. An illustrative example is provided in order to validate this property. In this study, the proposed solution is also compared with the existing solutions. The comparison results indicate that the proposed result is a more general and practical solution. Finally, numerical simulations are also conducted to demonstrate the practical significance of the proposed method.