I usually prefer a playlist of outdoor sounds: babbling brook, insects buzzing, bird songs, wind blowing, gentle rain. I like YT videos that feature cooking in a natural environment. The YT "Men with a Pot" channel is a good example.
Originally from amazon.com: Nature Sound Library.
Even though I'm mostly an indoors guy myself, hearing these things calms any nervousness and provides me with a feeling of inner peace.
There was a time when I used to fear going outside my comfort zone, and then I realized fresh air, sunshine, clean water, nutritious food, regular exercise, and adequate sleep is healthy for you. So every so often whenever I might feel tense, I step away from my usual (sometimes) stressful work, take a break, and enjoy some fresh air. It helps clear my head of any negative emotions.
If that's not practical for the time, the playlist puts me in a better place than otherwise. I also have learned to not watch too much TV entertainment, because that can sometimes be stressful in itself. Music is helpful in that it can stir your emotions, though I've learned to not play hard rock or metal if I'd like to relax. That type of music I usually reserve for vigorous exercise and blowing off steam. To soothe, it's back to the babbling brook and bird songs.