How can you heat 1 room of my house cheaply?

To heat one room cheaply, consider using a space heater, which can be more energy-efficient than central heating. Ensure the room is well-insulated by sealing gaps around Windows and doors and using thermal curtains to retain heat. Additionally, you can use a combination of layering clothing and blankets to stay warm without relying solely on heating devices. Lastly, maintaining a consistent temperature can help reduce heating costs.