Just wanted to share this with you guys (and see if it works for others). Virtually the only thing that helps me keep my cool is actually COUNTING how many times the other person is making the trigger sound/motion. I do it either by the “raw numbers” or in terms of how many times they are doing it on average per minute. The per minute one usually calms me down substantially within two minutes (I think it’s because it adds some predictability to knowing that it won’t happen more than X times per minute in all likelihood– strange, though, because predictability/anticipation of triggers typically worsens them for me, or so I thought).
A second technique is repeating the trigger to onesself. Have you ever been so pissed off that you wanted to just slurp a huge slurp right back in someone’s face or whatever? Well, I don’t do that of course, but I do do the thing as quietly as possible, to myself. That seems to alleviate some of the build-up. I got this recommendation from a friend.