First, put yourself in a place where you will be able to strike up a conversation with a stranger without it being too out-of-the-blue. A coffee shop or library could work well; personally I used a classroom. Once you are in your place, find a stranger who excites you sexually. Give them a name and a personality, maybe even a backstory if you’re feeling particularly creative. Fixate on them, fantasize about them, picture the two of you in all sorts of crazy positions all throughout the place you’re at. Allow your filthy mind to run its course. Now you need to find a place to bring yourself to completion. A bathroom would work well, but if you’re feeling particularly adventurous you could try to finish yourself in public (!). In any case, allow your mind to be absolutely fixated on this person and all of the delicious, dirty things that this person would do with your naked self. Make yourself come at the thought of them. Finally, when you’re done, and the opportunity presents itself, go up and talk to them. Introduce yourself and get to know them. See how their actual self compares to the fantasy of them you’ve crafted in your filthy, filthy brain. I’ve done this on a couple of occasions during boring classes, and the results have always been interesting. 🙂