Hmm, that's interesting. Apart from a small range of activities I know (through experience) to work (running, walking, sitting in a cafe, talking to my friend thelxiepia online), the most effective things tend to be very banal activities, such as the aforementioned German class. It's very much a process of trial and error, isn't it? You just build up a collection of methods for coping with it after many times experiencing these feelings. At least that's how it feels to me.