First of all, I make sure it is clean and in order. Clutter makes you think negative thoughts so do away with it. I also love fresh flowers or plants to give positive energy to wherever I stay. Calm and relaxing music and meditation. Light some candles with your favourite oils. I also put vinegar in small bowls and place these in some strategic places to remove odour. Opening the windows and letting fresh air in is one of the best things one can do.