My method is to come up with a phrase or find a phrase written somewhere nearby, count the syllables or letters, and take this value modulo the number of bins. For the topicstarter’s poll, I found a sentence on a whiteboard near myself, counted its letters modulo 10, got 5, so I voted for 30%, because the bins were like 20% − 30% − 50%.
My method is to come up with a phrase or find a phrase written somewhere nearby, count the syllables or letters, and take this value modulo the number of bins. For the topicstarter’s poll, I found a sentence on a whiteboard near myself, counted its letters modulo 10, got 5, so I voted for 30%, because the bins were like 20% − 30% − 50%.