Going on hikes in nature alone. This is my go-to relaxation exercise for when I am really stressed or I am facing tough decisions and tough times in general.
I may be alone, but, I wouldn't really want it any other way during those times. Being alone allows me to not have to focus on other people. It really allows me to not focus on anything at all. I can just keep on walking without focusing on anything specific. This allows my mind to calm down and relax, which then allows me to start thinking in a much clearer way, without the impulsive thoughts and emotions that I may have due to what ever the situation is in my life.