Deep Reinforcement Learning is essential for enabling smart 6G communications. This resource details DRL algorithms like DDPG and PPO for complex resource optimization in Unmanned Aerial Vehicle (UAV) networks and Reconfigurable Intelligent Surface (RIS) systems. Applications covered include 3D trajectory design, power allocation, and phase shift optimization, crucial for achieving ultra-reliable low-latency requirements. DRL is presented as the promising solution for overcoming scalability challenges in dynamic wireless networks.