This lecture by Dr. Giovanni Pizzi from PSI presents a practical guide to Density Functional Theory (DFT) simulations, combining theoretical instruction with hands-on sessions both on-premises and in the cloud. As the third module of the 2025 PSI course "Electronic-structure simulations for user communities at large-scale facilities," learn essential techniques for implementing DFT calculations in real-world research scenarios. The nearly two-hour session provides valuable insights for researchers and students working with computational materials science, offering practical experience with tools and methodologies used in electronic-structure simulations at large-scale facilities.