The sooner I recognize that I am having those 10% thoughts the more quickly I find it helpful to try to redirect my thoughts. Once I get into the deep thinking it's too late for me to do much other than 1) recognize that it is temporary, and if possible I will try to get some sleep; or 2) post here on SR that I am going through something -- to get it out on the table. If I catch it coming on, by recognizing that my feelings are valid, that I do not have to deal with them for the immediate moment, I often can just leave them behind me and not even have to come back to what's bothering me. Often that 10% is just self-manufactured "dreck".